Here's a fun craft everyone can try that is fairly inexpensive!

All you need is some puff paint from the craft store (Around $1 a bottle)
A brush
Some cardboard or other card (like cut up cereal box, etc)
And some socks that need a little livening up!

I used socks I already had that I didn't wear as much and thought I'd make them cuter!
I did some experimenting and found a thin coat works well and isn't too bulky inside shoes, but puff paint is inherently textured and has great grip when applied thicker (like stuff on slipper socks)! Allow extra dry time for thick applications.

Have fun crafting! :D