Foam stamps (the author used a set by Making Memories)
Cutting mat or some other item to block the paint from bleeding through the fabric
Apron or t-shirt
Wash, dry and iron items you will be stamping. It's best to have a clean, flat surface. Place cutting mat or whatever item you're using to stop paint from bleeding though between the front and back of the t-shirt or underneath the apron.
Decide how you want the letters/number placed. Load stamps up with paint and stamp out your message. Let dry according to directions on fabric paint bottle.
Wash (inside out if t-shirt) and dry.
Megan's tutorial was taken with permission.