Here is a possible solution.

Caveat:

There are many ways to quadrangulate this topology and I am not saying these are the best solutions Jay or one of the other guys that have done more organic modeling then me would be a better resource. I am sure, Jay's alien surfer dude tut would cover this kind of stuff very well.

In the top one I assumed you just could not tolerate an edge running around the front of the mesh so I routed it around the back and did a 3-into-1 reduction.

In the bottom on the top of the head I used daverave's suggestion and then redraw the rest.

On the bottom of the hat I just dont know what to say but the topology (because of perspective probably) looked completely insane. So I just removed it all and drew in the single edge to make 2 quads (top right) and in the main one I just did a extrude w/offset and the same split down the middle.