Well, here's my summary of what I do for Rufio. Obviously being Asian means some differences, but hope it helps someone out there. They say we Asians have it a lot easier when it comes to crossplay and I'm not complaining
I'm still learning. I always just see me, but friends say I pull it off so that must mean something.
This is the outfit I am discussing: http://www.cosplay.com/photo/3348893/
-Eyes: the hallmark of "feminine beauty" is wide/large innocent eyes that are somewhat slanted/catlike (especially for Asians). I naturally have small eyes, so for me I just leave them alone. A tiny bit of shading in the outer corners of the eyes to help make them more horizontal would help.
-Eyebrows: I never cease to be amazed by how much eyebrows shape a face! Generally, women pluck their eyebrows; men do not. I know a lot of girls may not have the time for this kind of commitment, but since I can, I grow my eyebrows until they lose their arches and become rather thick. It does SO much for making a face more masculine. (You just have to put up with having bushy caterpillars for eyebrows in everyday life)
-Lips: There was a well known study that made the rounds on the internet about how we naturally associate feminity with contrast in a face. So the less contrast the better - neutral colours. I just apply my foundation to my lips then gently blot it out to tone down the natural contrast. Very shiny lips are also feminine so don't touch the lip gloss or shiny lipstick.
-Complexion: Asian society has this fascination with whiteness (in the same way western society favours a tanned complexion). They find particular beauty in women who are flawlessly white. So for me, I tan the heck up - luckily I do this very readily (it takes me years to lose it though; three years of staying out of the sun, was a relief to let myself tan again). Then I use different shades of dark foundation/bronzer/face paint to generate an uneven complexion, and of course a smear of dirt here and there does much for a Lost Boy
-Jawline: Making more contrast along the jawline to emphasise it helps; I don't need to do this with makeup personally, but I found that posing in certain ways makes the angle of my jaw more prominent, and also lengthens my chin.
-Facial hair: This character doesn't have facial hair, but I still find that the faintest shadow of it makes people really question if you actually shaved to get in character, and helps trick the eye.
-Hair: I know most people don't have the time or commitment for this, but I personally get my hair cut. It helps to befriend a hairdresser who is fascinated by cosplay. She cuts my hair to a suitable boyish style. This means I'm stuck with it in public, but it doesn't bother me.
-Attitude: There are differences in the way girls generally pose for photos compared to boys. A sweet smile and head tilt are characteristically feminine; boys tend face the camera directly. See what fits for your character. Where possible I'll either smirk, grin like an idiot, or look suitably unimpressed.
It's a basic write up but hope it gives someone some ideas.
I've recently been experimenting with Caucasian mtf so will post those experiences next.