The figure eight knot not only looks cool, but can serve as a replacement for the overhand knot when tying a stopper knot. Its design means it won't become excessively tight and hard to undo, but won't slide up and down the rope.
Step 1: Prepare to Tie
This knot doesn't have any particularly hard preparations, just make sure you have the end of the rope you want to tie the knot on. It should be noted that with a bit of practice, the knot can also be tied using both ends.
Step 2: Tie the Figure Eight Knot
Begin by forming a loop with the end of the rope. Take the end, and loop it behind the long end of the rope, and then bring it out, and pass it through the initial loop.