I love doing this. I have found that it really depends on fashion trends as to what characters I can do. For example, Moana was super easy because it was so easy to find dark coral tops and khaki shorts. Same for Pocahontas (though the shoes can be a challenge with her). Ariel has been harder because I can't find bright green shorts or jeans that fit me well (they aren't easy to find in general). Belle, Cinderella, and Aurora are easy because the colors are simple. Yellow top and yellow shorts for Belle. Blue top and white shorts for Cinderella, or a blue sundress. Pink top and shorts for Aurora, or a pink sundress.
I like when I can have a few items of clothing and mix and match with accessories to change up the characters. Pinocchio, Winnie the Pooh, and Snow White (with added blue) can be easily mixed and matched with yellow and red. Ariel and Dopey can be mixed and matched with green and purple (and just green for Tinker Bell, Peter Pan, and Tianna (maybe throw in a little yellow).
The hardest part for me with Disney Bound is the shoes. I must have comfortable shoes. Flats do not work for me, and so many of the Disney Bound outfits I see online have beautiful flats or heels. I am always on the lookout for tennis shoes and sneakers (like Vans or Keds) in pretty colors like pink, blue, green, or yellow to wear with my Disney Bound outfits.
I google "Disney Bound" and click on "Images" and I get a lot of ideas that way.