I use foil trays a lot at home as I make meals and freeze them but I always seem to have loads of left over foil lids (as I usually freeze 3 meals and use one or I cook stuffing in them) but I've found a great use for them! They are great to put through a die cutting machine to make a mattish silver embellishment so great for Christmas plus fingerprints done show up as easily as on mirri-board.
They also emboss amazingly and done cracker (unlike some cardstocks)
I used a mix of spellbinders, sizzix sizzlets, Tonic dies and Darice embossing folders (plus one free from Simply Homemade). They cut great in my Big Shot and came out so easily.