This one is an oldie but a goodie.
This was just a quick indoors make-up test, playing with some old theatre stuff I found. I wanted to do a really dramatic transformation and I hope I pulled it off.
How I did it:
For the girl's face, I stuck with a neutral palette and started with a shade lighter than my skin tone and went around my eyes (on the tops of my cheek bones), over the top of my nose, and across my forehead, blending as I went. I applied a tiny bit of brown eyeshadow for a little bit of further definition and used a lip-liner to exaggerate the curves of my cupid's bow (the dip in the middle of my upper lip). A little dab of blush later, and I was done.
For the man's face, I started with the eyebrows. I drew them in much thicker and almost straight across with thin strokes of a brown eyeliner pencil. Then with the same brown I used for the beard, stippled across and under the brow to give it a little more definition. I went a little around my eyes and at the sides of the bridge of my nose. I gave myself alittle bit of crow's feet, and smudged some eye shadow under my eyes, for a tired look. I also went over the lines on my neck, and even put a little dark concealer across my chest. Then I tucked my long hair into my hat, stuck out my jaw, stole my boyfriend's leather jacket, and pulled on a "grumpy" look. Ta da!
A rule of thumb...
For a feminine look, you need high, arches, thin brows. It's important to have make-up to accent the eyes, to make them look larger. The goal is to look youthful. The accent is all on the upper half of of the face: hair, brows, and eyes.
For a masculine look: thick, straight, darker brows. A little bit of aging can help - crow's feet, circles under the eyes, droopier eye-lids. The accent is on the lower half of the face: a larger nose, thicker jaw-line, and of course facial hair.
It's not always true for all peoples, but that tends to get the idea across when doing this kind of work, either for theatre, cosplay, cross-dressing, photoshoot, etc, etc. This is just what I've learned, and what I use whenever I... need to be a man. Which doesn't happen very often. Sigh.