What I used (materials can be purchased at most hobby stores like Michael's):
40 inches of 1 mm leather cord
Beads
Size D Nymo thread
Beading needle (personally I use a floss threader because I like that it's flexible without getting warped in the beading process - also any size thread will fit easily in the loop)
Beading glue (I use super glue because the bead glue I have turns white and crusty when dry)
Button with 2+ holes (needs to fit 2 mm cord, look for spare buttons around the house)