Take a small piece of reindeer moss and place a drop of PVA glue in the center. (See photo above)
If you want to add thread to the ball after, form the ball by rolling it around on the palm of your hand. For a 1:12 scale kissing ball, the ball of moss should be just under 1/2 inch across. For a 1:6 (playscale) ball, make your moss ball close to 1 inch across, and for a 1:24 scale ball make it about 1/4 inch across.
Set the ball aside to dry.
If you want the ball to look like it has a ribbon running through it, make the ball following the instructions in the next step.