Opaline Pearl

Appearance
Time to let your imagination run wild! I must say this step is VERY enjoyable, as artist and a writer. However, don’t let that get into your pretty head, okay? When designing your character, think about why the character wears what they wear, and how that defines them as a character. Don't just add things to try and make them "unique," let the character be told through their appearance. Keep it as simple as you can, simple characters are more iconic and easier to view or read about.

My advice for this step is to find an anime/chibi maker. Not only is it fun to play around with, but you will also grasp the concept of originality, and can also avoid being sued by the artist whose art^ you might have borrowed as reference for your supposedly Original character. Here is a good one: http://gen8.deviantart.com/art/Chibi-Maker-1-1-346025144

^You can either draw the concept art yourself if you have the time, or hire an artist to do that for you if you have the cash. Remember to provide them with plenty of details and reference images.

As I said above, whichever race you are going to choose for your character, has to fit in its the universe, and this applies to the appearance as well. Don’t make your character an elf and dress her like an android, or an innocent angel dressed up like a playgirl.

Personality
Oh man, this step makes or breaks your character. This combined with your character’s Abilities, this WILL determine if your characters is a Mary Sue/Gary Stu or not. Take caution when dealing with this and also during the later steps.

Think outside the box! Avoid clichés like the “Shy and sweet girl” or the “Lone wolf trying to do everything by himself. I’ve talked to people about originality, and some of them stubbornly say that “Originality died long ago!”. Which is WRONG! Originality isn’t a concept that someone hasn’t used/thought of yet, it is about a combination of what already exists. However, take note that anything you are going to combine has to match and create a smooth flow for your character.

Another small step is to put your character in every situation you can think of and see what he/she will do in those situations. This step is to check for flaws^ in your character or if some of the personality you gave them conflicts with itself.

^By flaws I don’t mean there is something wrong with your OC. Flaws are perfectly acceptable, I even encourage you giving your OC flaws.

History
History builds your character. Everything about your OC, from their appearance, clothes, personality and ability has a history. Who gave your OC their clothes? Where did that scar across their cheek come from? History ties your character together, so do a lot of research, and try to avoid any contradiction.

Here is when things gets tricky: The future is wide open for everyone, and each and every single one of them can choose from various options, so keep your character’s future open for them to follow their own path EVEN if they are destined to be the savior of the world (In which I don’t recommend since it’s cliché). Let them choose whatever they want (and maybe they can have a nice breakdown of choices), leading them around and back to the main goal that you have planned out.

Abilities
What can your OC do ? From the simplest, everyday activities like cooking, cleaning or doing laundry to the most complicated thing you can imagine, like mixing chemicals (without blowing anything up, or at least, not by accident of course). Go wild with this step, an example could be a chef who can paint, a singer who can play soccer or even a puppy who can do the grocery. However, make sure it all matches and won’t create any conflict later.

Another ability I should mention is their ability in battle, especially if your future book/role-play is action-related. Now, I’ll cut to the chase and say it right now: Do not make your character Over Powered (OP). Start small if your OC is a teenager, let them grow with time as no one is able to actually master anything during their teenage years (Except maybe throwing trash in that trash can from 5 feet away – and there are chances that they may sometimes miss the target.). Let your character grow through time, master some special ability – small at first, but stronger as time passes.=

^A big warning to all of the new writers who are reading this: You can’t have the best of both worlds. No one can, and should anyway, even God. Characters with perfect Personality and Ability WILL be addressed as Mary Sue/Gary Stu and will be hated by 99% of the writer population. While you can give your character a negative personality such as them kicking puppies just because they feel like it, you can’t do the same with this step.

My advice: Balance, balance and balance. If your OC is an archer, make him/her unable to perform close range combat, or physically weak if they are a magician. If they are smart they would avoid meaningless battle instead of heading blindly into one. Be specific and very careful to write down their strengths and weaknesses.