if the program you use has bones you could try to use that. i am learning about 3D and most of the stuff is done with that. i am not an expert in 3D work btw but if you don't want it to move with the body as well as have a natural bone structure for moving around you could try that. otherwise you can look it up on youtube.
but further looks great (just keep and eye out on the eyes. if you want to texture it, it is better to keep the surface flat or a bit hollowed in (and not so far back) or make it a bit sticking out so you can paint over it. this way you add more character to it as well if you look at him from the side. but that's my opinion mabey you have a plan for it that i don't know :p) anyway further than that looks great keep the good work up.