Since I've already discussed Bolton as a character in other places (see link below ;)) I'll take the opportunity to instead talk about my thoughts going into designing her.
I originally made her when I was 11, and the entire idea was just her fulfilling the role of a significant other for Yorkie. Because I was 11, I took the opportunity to add in a lot of traits that I found attractive at that age, which for me at that time was her red hair, and glasses. Her original design from that time didn't have her bangs covering her eyes, but I wanted her to have that trait (something I've always also found attractive). At the time though, it was 2010 and Panty & Stocking was very popular, and I was worried I'd be called a copycat, seeing as Brief also has orange hair with a similar hairstyle.
Before designing her, I had already decided on the name "Bolton" I thought I was very clever for having a lightning motif (Get it??? lightning BOLT?? Eleven year old me was proud). Otherwise I gave her some very basic jeans, and some yellow shoes to match the lightning bolt. As you can see, because I was 11 the thought process was pretty shallow.
Fast forwarding to 2019 when I revamped her design though, I obviously decided to keep a lot of these traits. I made the jeans more ripped to emphasize her punk band member vibe, and the combat boots are meant to serve for that purpose as well (they're made to look like the style of combat boot I wore religously for several years). I made her shirt into a crop top and also a ringer tee because I thought it looked nice (maybe I haven't changed too much in those years after all). The suspenders underneath looked really cute and very anime-y (seeing as 11 year old me was majorly inspired by anime, it felt right). Since I can draw more than one body-type now, I had to decide on that, and I went with this thin angular sort of look. I enjoy drawing the way her limbs are thin, but don't taper.
Speaking to where her fashion sense has landed in general, when I'm making outfits for Bolton I often think about how she values comfort a lot. She puts effort into her looks, and she's good at coordinating, but since she often touring (which is very tiring), she wants something comfy and cozy to wear. She's all about big t-shirts (often Yorkie's), big fuzzy fleece pants. She also leans a little collegiate, think pleated skirts, suspenders (OVER her shirt this time), or sweatervests. Lots of plaids and patterns for her as well, all with her punk fashion flair.