The reason for this will be the next post.
Step 1: Cut a piece of cardboard the lenth you want your pom pom to be

Step 3: Wrap the yarn continously around the cardboard. The more you wrap, the fuller the pom pom will be.

Step 4: Slide the wrapped yarn off of cardboard and tie and knot tightly a piece of yarn around the middle.
This brought back some memories – when i was little my mom used to keep me busy making these while she knitted :)Thanks for reminding me
you can use your thumb and forefinger with a space instead of using a cardboard. i learned this from a türkish tv-programm
thanks for the tip!