Sketchy skeletons in a closet

[Kosheh]

hoooo lawdy, look at dem skeleton buttcheeks on that there lefthand side
(actually, this reminds me of a skeleton from like Banjo-Kazooie or something)


Not being obnoxious here, E-Man, but what kind of character are you going for? The current skull makes me think it's for a stocky male...
As recme said, there's nothing wrong with using a frame of reference while drawing one. It doesn't have to have every crease and nook and cranny, but as long as it adheres to basic structure, you should be okay.