Tighter fighting clothes are typically seen as more feminine, where looser clothes are seen as more masculine. Try finding lower-cut shirts and shorter shorts as well. If you have access to makeup, a little bit of mascara can go a long way. You can also try shaving, like your legs and armpits and stuff. ((I'm assuming you're amab?))
Those are just some tips I've heard from some of my trans girl friends, lmk if it's helpful :3