A Step-by-Step explanation.

1) If you have a story idea but require a character, the best would be to consider what kind of protagonist you would like to start off with:

• Does your character start off strong but ends up weak?

• Does your character start off weak but ends up strong?

• Does your character discover themselves in the book or are they already self-assured?

• Is your character convinced they are a vampire but is secretly a werewolf?

Stuff like that. Before you start planning your character, you need to understand a bit about what you want them to become. Work from back to front. 

2) Now you have a bit of an idea, now it's time for research and planning. Let me give you an example of how I plan them:

Let's say I want to create an OC for Harry Potter (yeah let's roll with that), then first off I always use powerpoint.

Yes, you read correctly.

Because I need to be excited about the story in order to get others excited.

The first thing that I do is get a landscape picture that can introduce you to the story you're about to write. In my example. I will use Hogwarts.

In powerpoint, I choose a nice theme (because it looks good) and use the landscape picture as the background. Observe:

Another reason why I do this: I use this method for each and every single book I plan, becasue it helps me remember what the story is about (or which anime I'm writing about, usually)

Don't worry about the title and description for now: you can only choose an appropriate title after you've planned everything.

3) Create a new slide. Now, I have a default template for character planning I use. It looks like this:

Of course, not all characters have 'weapons' so you adjust with your specific character, like also adding 'orientation' if it's needed. Now, I copy this into my new slide and this will be the protagonist (or antagonist if that's what you're going for) and I always place it in two columns.

  4) I don't immediately begin at the top of my list (unless I had an epiphany) but I always start with a picture of what the person in my head might roughly look like. Let's say I want to invent Luna Lovegood's older brother (that's a scary thought!) then I know a few things immediately:

• Blond hair

• Most likely also a bit crazy like his sister and father

• Most likely also a wizard

• I can't picture this huge muscular man in my head, so we're going for a little more Draco style

• Ohhh maybe he can be Slytherin but Luna is so chilled she doesn't care

• What if he frequently gets detention by Snape?

• What does he like? Hm... dragons. He wants to be a dragon breeder

And that, ladies and gents, was an accurate description of how my mind began to flow. Just sit back for a while and begin to think. Also, don't forget to write all this down, no matter how stupid it might sound in your head! It might make a good plot twist later ;)

So now, this is where I search for a person to fit the person in my mind. I have Luna's picture up on one side of my screen so that I can look for resemblance but obviously, not all characters are a part of fanfictions and then you can just search for who you want. E.g. my dearest Princess Melanie appearance just struck me! I knew I wanted her hair violet, and from there on I just searched.

I type in things like 'blonde hair boy' or such boring things and if I find nothing I usually add 'tumblr' with. That usually works.

And so, let me introduce to you Luna's imaginary brother:

(Obviously, if you're going for a sibling relationship or parent relationship to a character already existing, don't beat yourself up if they don't exactly look like they belong in that relationship. It's not a movie you're creating here, it's a book with words)

5) Alright! So I have his face (which is gorgeous btw) and a few facts I jogged down earlier. So now it's a bit of time for research:

• I'm going to start with his age. I know he's Luna's older brother, so let's say the story is set in the first HP movie. Or book. Don't kill me. So I google 'how old is Luna Lovegood in the first harry potter' and don't get an immediate answer and I quickly realize she isn't in the first one. Great. Not to worry! Plan B! We go to her wikia page (I love that site) and I see this:

Great! Now let's find Harry Potter on the same site:

One year age difference. Alright, alright. Now let's see how old are students in their first year:

Information! Great!

So HP was 11 when he started in the first book, so Luna was 10, that means our OC has to be older than 10. He can't be 11, unless the parents were rabbits, and by personal experience, I know parents usually wait 3 years after their first child before getting pregnant again. So, add the nine months of pregnancy, gives you roughly 4 years.

Nice man nice! He's 14 then!

Now we can get some more information off of Luna's site:

Obviously, they will have the same family, so I chart down those who I only care about. 

And let's see if there's anything else I can use...

...

Well, now what am I supposed to do? Eeny, meeny, miny, mo!

You shall be pure-blood!

Now, look at everything we already have:

(At family, F - father, YS - younger sister, GF - grandfather; etc.)

We're picking them off one by one!

So, he's 14, that means he's in his fourth year of school. And he's a Slytherin, that means there has to be a reason he's one. So... let's think personality now.

6) Personality is possibly the most important aspect of a character. Even if you don't know the name of your character and just write out of the first person, how your character sees life and treats others is a reader's first indication of what kind of character the protagonist is.

So, our little man here is a Slytherin and a bit crazy, so that gives us a foundation to work with.

Now, I know a lot of people usually define their characters by the sixteen personality types:

Personally, I think this is restricting your character to be one type of person and have never used this in my life. But if you're really stuck then I guess it's okay but your character's personality is of your own choosing, not according to some category.

For example: my baby Lovegood will like dragons, but not because they're badass, but because he likes animals like his family member, Newt. Yet he's a Slytherin, so he does have some sort of cynical side.

So let's say he loves animals, but hates wizards. He thinks they 're destroying nature and taking away the magical animals. So he has a soft side and a terrible side.

That doesn't make him appointed to one type of personality.

So a few words to describe him would be: green thumb, dragon-obsessed, gentle to nature, dislikes humans, believes everyone acts only out of self-interest.

From this, we can almost assume the rest of his personality. A few keywords are all we need really to get us going. You will learn your character as you go on.

If you truly are lost, just pick a few random words and see what happens:

7) The rest.

Birthdate: well, Luna was born in 1981 so he was born in 1977. We can make up a date or if you're into that Horoscope stuff, then go for it. I mostly care about the year.

Height and weight: sometimes they're important. In this case, they aren't really since I described in his appearance that I see him as thin and tall. Slenderman-ish.

Occupation: in terms of people still going to school, I would usually put that they're the vice-captain of the book club or they play Quidditch but Luna's brother is not that type of person at all. So, he's just a normal bloke.

Relationships and enemies: this I usually fill in as I plan the rest of the book, but if I had to think quickly, I would probably say that Draco doesn't like him all that much since his sister is a Ravenclaw, and maybe since he keeps getting detention with Snape, he might form a mentor-student type of relationship in the end? (relationships aren't just about love)

Hobby: now this is incredibly important. Why? Well, maybe you do have an entire storyline planned and there is no free time for your character to express what they do in their free time... wait, does that sound right? A person who doesn't have a hobby? So... inhuman. Harry had Quidditch, Hermoine had her books and Ron had chess. They did things in their free time, therefore they are relatable and human.

So, now the question is, what hobby would best fit your character? Here are a few to help you get thinking:

And there's so much more! So, let's think in terms of our Lovegood brother:

He likes nature, we established that, so he needs to do something outdoors. Gardening, obviously, and he seems as the type of person who would in his free time go onto a hill and just relax away from everyone else. Would he read a book while he is there?

Probably, seeing as his sister is a Ravenclaw, so he does have some of those genes most likely. 

Anything else he would be doing in his free time?

Dragon-breeding.

But maybe when he's older.

Weapons: yeah, no.

Abilities: he's a bloody wizard, but the question is: is he good at it? No, no he isn't. He's the type to skip lessons to take a nap outside and because of this, he gets into detention easily and his magic suffers. He's the type to attempt transfiguration but end up blowing the person up. 

And so, we have everything we need! Except for one detail...

8) His bloody name!

Hogwarts is set in the UK, and he was born in 1977 so we have to be appropriate in choosing his name. Of course, just look at this bloody father's name... we can bend the rules a bit.

So, I start by looking up the most popular baby names of 1977 to start with. Here are the top 15 of that year:

Do any of these suit my character? Hm...

Maybe Joshua. We'll put it on the list.

A quick search to other websites about British boy names gave a few options that caught my eye:

Joshua, Daimon, Gordon, Clement, Aiken, Benedict, and Milton.

Now you can go the meaning of names if you want, but I choose the one that I think best suits the character. In this case, I like Aiken. The name can have a nickname and he can have an alias, but I don't think it will be needed.

And now, we have everything for our character!

... that is on the list.

9) Extra detail.

By what I mean is: firstly, his pet. Secondly, his wand. Thirdly, his background. So these details are added mostly to fanfictions (except if the background of your character is important) such as for Tokyo Ghoul it would be what type of kagune it would be, for Naruto their nature affinity, for Doctor Who it might be describing the species.

Pet: so, a toad, an owl or a cat. Since he likes dragons, he'll most likely want to go with something closer to it to get used to it. So, an owl then. Here are the options:

Now although I couldn't find Luna's pet for reference, I'd say the family aren't overly caring about wealth (I mean, did you see their house?) so I'll have to go with the Brown Owl. Wait, it needs a name now. Hm... Tony. Yeah, sure.

So for his wand: you can go for the detail. Right now, I'm just going to use a random wand generator. (http://www.springhole.net/writing_roleplaying_randomators/magicwand.htm) the result:

The wand is made of white pine and has a core of barghest hair. It is 11 inches long and is pliable. It is very lightly colored and is roughly carved.

Background: For your own character, go into detail. For my character, he has lived a fairly simple life as far: born and raised a Lovegood, loves dragons, his family approves since they're a bit weird and then went off to Hogwarts like they expected of him. Not much to it. He has a good relationship with Luna, I would think.

Now, IMPORTANT, is to keep a list of the likes and dislikes you bring in for a specific character. You can plan them all out if you want, but I prefer to go with the flow and then keep track of them.

10) And now, unless you have any other character you want to create, you are done with that part of the planning!

A beautiful reference, especially when you're on hiatus and need to remember later who your character is!

So, if you doubt that I really do this, for those of you who know my book 'Mondo Pastello':

Oh yeah. It's totally my thing. You'll see more images of the slides as we continue with the planning!

(Also, this character is up for adoption so inbox me if you're interested :))