I kind of did this one for fun, and as an experiment to see if I even knew what the hell I was doing anymore. I don't traditionally draw Sonic in his "traditional" style, but lo… I drew some Sonics.
Drawing these, there are some rules/guidelines I found myself adhering to. I'll list them here, to give struggling artists an idea of my point of view:
-The muzzle doesn't wrap around to the quills. It stops nearly halfway around the head. It protrudes ONLY SLIGHTLY past the eyes, at most.
-The mouth shouldn't really float off to the side of the muzzle, unless you're going for a "style". Try to keep it centered. Even his signature smirk should be anchored to the front of his face, and creep towards the edge.
-The muzzle is more visible from low angles (looking up AT Sonic), or when his head is tilted back/up. Draw it bigger. On high angles (looking down), his muzzle is slimmer, because you see less of it.
-Sonic's brows normally float OVER the peak of his eyes. They only creep down his forehead, towards his nose, when hes scrunching his face…either in anger, or a cocky smirk.
-As with above, the blue part of Sonic's face between his eyes doesn't "scrunch" (into that double-bump) unless he's being cocky, or angry. That double-bump MUST match the eyes, or it looks stupid.
-The muzzle and brows are NOT flush with the face. You can see this, because I left them un-darkened. They protrude off his face, which is NOT a perfect circle. The circle is a guideline.
-The shape, softness, and size of various aspects of Sonic's head depends on his mood. Happy, angry, sad, shocked and tired expressions should NOT have the same-looking eyes, ears, mouths or brows.
Anyway, that's it for the heads. Hope you all get some use out of it~