I cosplayed as Rock Lee once, at A-Kon 19,...and it was SO hard trying to look like a man while wearing spandex.
I'm a theatre major, and I know my way around a makeup kit, so I employed a great deal of makeup on myself, even using light nude lipstick to make my lips look less full and squaring off my jawline.
I have a straight-up cartoonish hourglass figure (literally 36" - 24" - 36") so I bound my boobs and focused on trying to minimize my lower half.
I wore Spanx (ACTUAL Spanx, not the knockoff kind...they're so much better), wore wedge ankle-boots that I modified into ninja shoes (more height makes your legs look slimmer, and the wedge can give the illusion of a flat shoe sometimes) which I covered up with the leg warmers. I also opted for Shippuuden Rock Lee rather than pre-time-skip Rock Lee, simply because the Chuunin vest is nifty and added bulk to my waist and shoulders, whereas pre-time-skip Lee just ended up making me look very slightly pear-ish (spandex unitards cling to your curves something fierce, thus emphasizing my small waist in comparison to my hips.)
It worked pretty well, I think.