Here are a few tips that I've learned as general rules when face creation in Oblivion and it works in Skyrim too:
High cheekbones
Low eyebrows/thin eyebrows
High forehead
A slender jaw
A short small chin - a larger chin will do (but not so large its masculine) and porportionitly wider (but not too wide)
A slender nose but not too small
For looks you can either go for pouty lips or normal sized, but not small
Look at the face from the front and sides their should be symmetry between the jaw lines and cheeks
Take a look at beautiful models and study their facial structures and try to copy. I find the facial creation kit in Skyrim to me to be more limiting in certain ways than Oblivion, but they do have better presets, and it is much less complicated.