Alright I've got a mentee here (Christian223) who thinks he can learn a thing or two from me. If anyone wants to jump on board, please send me a pm, I can probably handle one more.
Anyways, I've decided to start you (christian) off with head studies, then anatomy as a whole. I know you've already done the heads, so go ahead and post them, along with 3 or 4 heads you drew from your imagination, using the knowledge gained from the studies that you did. This will be good fun, As I am looking forward to learning a bit myself.
Also, on the heads from imagination, don't focus on features, but rather the general placement of things. This is most important.