Tips on making different head shapes for puppets?

[ralbetis]

Hello! around two years ago, with the beginning of my interest in the Muppets, i spent the summer dabbling in making foam puppets. I still have a lot of foam and fabrics left, and as soon as i have time again i'd like to return to this hobby. But there's one thing that's keeping me from going through with some of my ideas - the only head pattern i've used so far is a basic round one, and i have no idea how to get into making different head shapes. I'd specifically like to learn to make a sort of lemon-shaped head, as well as elipse shaped ones, or ones with beaks, muzzles, snouts and whatnot. How can i get started on this? Can i make it work with foam sheets like i've done so far, or would it be easier with carving out of blocks of foam?
I would appreciate any advice i receive. Thank you in advance! keep believing, keep pretending