Underwear doesn't matter that much to be honest. If I'm at that point where I'll see your underwear, I'd focus on doing even more and something else.
I like decent clothes (not too exposing). Simple summer dress will work like a charm, jeans is the safest choice. You can go for skirts or shorts if you wanna have some trendy touch. (With a cute top of course) Good luck :)
Underwear: Top five most attractive panties- 1. Cheekers/ cheeckies (whatever the hell they are called) 2. Normal thongs 3. Tanga 4. Boyshorts The only panties that are a turn off are granny panties that cover your whole butt.
Regular clothes: I like yoga pants, tight jeans, leather/denim jackets, sweaters, and flannel/button downs. I also find it really cute sometimes if she wears a beanie :). Anyway, i love a girl that has style. Boring clothes are just... boring. And please... no sportswear. God i hate sportswear on women. Oh, and in the summer, simple jean shorts with a cute tanktop would be nice. My crush has this particular pair of white cut off jean shorts... OMG 😍