Yarn and Thread
An old time favorite, whether you're making a blanket or embroidering a pillow, there's always a use for sewing and crocheting.
Paper and Scissors
We all have scissors and paper, one of the simplest crafts you can make are paper snowflakes, or you could find an interesting origami pattern to attempt if you're brave.
Hot Glue and Determination
There is no limit to the knick knacks you can bring to life with hot glue and assorted craft supplies. Maybe try making a ferris wheel out of popscicle sticks. If you have an idea, there's probably a way to make it happen.