Gather embroidery floss, yarn, or thread
Cut a piece of cardboard to the desired tassel length
Wrap the thread around the cardboard multiple times
Slide a separate piece of thread under the wrapped strands and tie it tightly at one end
Cut the wrapped strands at the opposite end
Remove the cardboard
Wrap another piece of thread around the top to form the tassel head
Tie securely and trim any excess
Even out the bottom strands by cutting them straight
Attach the tassel to a cord, keychain, or project if needed