draw your design on a piece of paper to look at when ur carving ur design
the paper should be the size of the craft foam board
also, dont make it too detailed cuz it'll be too difficult to carve
if ur going to include writing, make sure the letters are backwards

start carving your design on your foam board (i dont know whether its craft foam or something similar >.<)
use a pointy object that is not to thin or sharp to make ur design
also, you should carve your design kind of deep but be careful to not go through the board!

use the paint roller to apply paint to your stamp but make sure it doesnt go into the lines

press your stamp face down on some paper and there is your print!
u can also use more than one color, but it didnt go so great for me :p

clean your paint roller and stamp, and save your stamp in case u want to make more prints :]