Step 1- Trace your little (or in my case at the time, massively swollen) tootsies on some cardboard and cut them out. You need a cutout of both feet so that you can make both at the same time. You especially need both if your feet are different shapes or sizes like mine (ew). I used a cereal box.
Step 2- Once you have your foot cutouts, stare at them for a moment thinking about how weird/gross/amazing feet are. Snap yourself out of it. Flip the cutouts over (so that the bottom of your "feet" are up) now you want to slip your socks over them. I got these cute socks from the dollar store. Love. Make sure to carefully line up the bottom of the socks correctly on the cutout.
Step 3- Take some puff paint (I got mine for about $0.75 each at Walmart about two years ago and have used them for about a million different projects) and start making designs. I used a combo of dots and squiggles . I kinda wish I'd just done the dots, but that's just me.
Step 4- Let the puff paint dry for the time suggested on the packaging and put those puppies in your hospital bag. Allow complements from the nurses to follow. :D