I've been having a lot of issues doing heads at different angles with the sphere construction method - I have a hard time placing the jawline and features even with guidelines.
Bridgman has a 'cube construction' method I've been studying from that I've found a lot easier. I'll have to scan in my studies a bit later -- I'm still working on them.
Charmer: Thanks for the link -- I've been meaning to give that site a try.
And if anyone wants me on skype, I'm "resident-bishounen"