Jaguar, Verlinden, Hornet, Yanks, and others make some nice heads with some pretty animated and expressive facial expressions. You can build up heads using Apoxie Sculpt, Super Sculpey, and Putty if you want. (The rule of thumb is if it works, it's good to use...)
You can find heavier foil that can be burnished flat and the "crinkles" removed from the top of champagne bottles, empty putty tubes or glue tubes, the foil used in hvac piping and duct, there is a tape available from the hardware store that is used in this application that is great for this purpose, solder sheets for plumbing or electronics, stained glass suppliers sell a copper foil for caming, masking tape, the foil off the top of jello pudding, lead sheeting used for fascia work, or around chimney bases. You can also get away with paper from your laser printer or notebook, electrical tape and or flattened and rolled solder.
Mike
"Imagination is the dye that colors our lives"
Marcus Aurellius
A good friend will come and bail you out of jail...but, a true friend will be sitting next to you saying, "Damn...that was fun!"