Long ramble of venting to help.
My best advice is to start by thinking of an inspirational fetish to get you started. And always experiment. Even if it looks bad, toss it away for future uses.
I'm always a sucker for kunoichis and female samurais thanks to anime and japanese culture. Now how do I make a character of these inspirations? Simple. Experiment trial and error. Find the best look for your character that just makes it look....."wow". You want to do that to an impatient and ignorant fool. Wow them to say nice cas.
I'll use my original Rei Hayashi for an example. Not many people care on story, but generally about how a character looks in general. Let me show you how I got Gatsu's attention for instance.
Rei at first started as the typical cliche anime chick with a spunky attitude.
Inspiration first began here:
My thoughts were just remaking this character in the best way I could. My result was this:
Not bad for a start right? Wrong. Though this is average start of character with potential, one thing you must always stay away from and I repeat stay away from, is looking too cliche and trendy. Cliches are fine, but they need to be unique. Online has many chicks named Sasha or Jill or whatever anime fantasy chick I find wearing this same armor. They're cute, but they're forgettable. You don't want to have people say "cool story bro" and then just leave it be. No, you want them to look and praise your creations without any sugarcoat bs. That's why it's best to try something new to keep it unique.
That being said, I found this outfit to be basic for the typical samurai chick. But as I saw better customs from others than this particular look for Rei, I became competitive. Being competitive is always good. Being a mushy gushy humble guy is my style, but being competitive brings out the best in everyone. So after I saw some great CAS and style from certain people like Gatsu, I felt I wanted to improve and be more experimental.
So I googled and searched. Another thing you should always do for "fetish ideas". I found nothing until bam I found and unlikely source.......this pokemon. Suddenly, I felt it could help with my character Rei Hayashi in terms of making her look cool yet odd at the same time.
Here's a pic of inspiration that improved my original Rei Hayashi. It's name is Bisharp. It looks like a power ranger/kamen rider but screams don't underestimate me. I felt this could suit Rei.
My initial thoughts were to recreate and follow the color scheme meticulously and find parts similar to this pokemon. But as I build it, I happened to get inspiration from Ayane from Dead or alive in terms of her fashion. And my end result got me a Gatsu like. And to me, I'm astounded of how far she's improved. Anyways, her new look.
Basically a tldr version is rip ideas from you favorite characters or any fetish in fashion and culture and try to combine them as one.
As for story, well make it cliche believable. In this case, Rei's gist of a story is a tomboyish, nice, and sassy Samurai lass that loves to fight. Rei is prone to be a bit quick tempered if you treat her wrong. Although she uses Dual Katanas which was my main objective for this ex samurai girl, a Katana and Wakazashi is fine. But at least with this look, I can picture as a minor character for the Manjitou. Who look odd yet awesome for ninjas......another inspiration...
Hope this long ramble helps.