Commentary
There's tons of great ways to do a realistic drag costume. You'll definitely want to shave first and invest in a nice foundation to even out your complexion. (Liquid works the best, particularly if you're not really a frequent user of makeup.)
You'll want to camoflauge your eyebrows and can do so with a cosmetic putty to layer over the top of them. Once it's dried, put a layer of liquid foundation over your face.
The key to a realistic foundation is to blend, blend, blend with a makeup sponge. Make sure you blend the foundation onto your neck, too, so it doesn't look like you're wearing a mask. Set it with some powder after applying.
To give your face feminine contouring, use a bronzer in the hollows of your cheeks. Suck in your cheeks and apply it with a large, fluffy brush to the hollows. Add just a bit of the bronzer around your hairline and along your jawline and down the center of your neck.
You can get a nice, inexpensive wig. To give it more of a realistic feel, add some hair ornaments.
You probably won't want to shave your chest, armpits, or legs, so choose your gown carefully. Even if you do have leg hair, pantyhose might be uncomfortable after awhile. THe hair on your legs might feel "pulled" by the nylon of the fabric.
Long gloves are a good option to cover arm hair and a long gown works good, too.
For realistic (non-lumpy) boobs, go to a store or online to find some "chicken cutlets" to stuff into your dress. They're supposedly very comfortable and are designed to stay in place better than wadded up toilet paper or socks.
Good luck!
The prime female character I have in my costume inventory is that of The Domestic Diva Martha Stewart,
I have four outfits for Martha as well as the Martha Stewart apron to do the kitchen scene.
Since this is a new character development, I am anxious to see how it goes over at a future function.
I plan on dressing as a female (again) this year, I like to appear as "real" as possible.
This year I am thinking of dressing in a costume for a female & need some ideas.