i've just found two things:
one, if you crumple the foil into a ball it IMHO looks really cool. the good point is that flaws from the gluing process don't matter and the clear coat with adhere.
the second point is a little less good. you can make a very cheap copy of the fender aloha aluminium strat by putting tons of glue under the foil and scribing with a blunt pencil or old biro.
just some ideas, what do you think??
also, on http://www.mr-office.com you can buy rolls of metallic paper.
would this be thicker than tin foil therefore reducing flaws??