Its not always easy drawing friends or people you know. Sometimes they can be insulted at your interpretation of them. I have a hard time drawing people that are unattractive or I cant quite grasp. I have actually had a couple of girlfriends I couldn't draw for shit. Here are some images of friends I have done over the past couple of years. Let me add, I have drawn some friends and I have no idea what the hell they did with the images.
This is Heidi and she rules. She was easy to draw thankfully because she has dark hair. I hate drawing hair so much. In case you cant tell, she plays guitar.