(I know the picture is a really bad quality but it's my earlier Mary-Sue!)
So this small chapter specifically applies to the original characters that get drawn but can also apply to the Marvelous writers that know what description is.
What clothing a character wears will no doubt be linked to a variety of things e.g. Wealth, interests, personality. But there are other things to consider as well.
For instance, make sure you check what clothing actually existed in the era you're talking about.
I'd also suggest making whatever clothing you chose to dress your characters in is appropriate. That bikini might look super cute but please don't wear it to school. CanYouBelieveThatI also brought up a good point in the comments about skirt lengths which would be good to read over. We all know about too short but they brought up the point of fighters in long skirts. Check it out in the comments.
And while I'm on the topic of bodily exposure, not all female fighters need to wear skimpy armour that barely covers the stomach. I go to comic con, I know that some girls do but typically these are the women with great figures. What I'm trying to say is that a lot of 'perfectly shaped' Mary-Sue's wear skimpy clothing that is totally impractical and just draws more attention to them.
This of course applies to the good old Gary-Stu but normally these guys are just shirtless.
@Insanity_isnt_dead also pointed out that the status of a character would have huge implications to the brand of clothing they wear. A poorer character wouldn't wear designer clothes and if they did own something expensive, they would be incredibly proud of it. Be careful of this and again, read the original comment.
Both suggestions are written better in the comments.