You will for this some nice sharp nail scissors, (optional an Exacto knife), some scrap cardboard like you find from shoe boxes or scrap bristle board, a ruler or measuring tape, a cross-stitch size 18 needle (recommended) and of course your choice of various colours and textures of yarn, what ever you have lying around.
A word of caution, only for older children and not so clumsy adults should be working with sharp scissors and knives. ;)
Young children below 10 should ask their parents or guardians to cut and do the more complicated threading.
Oh yeah I like to apologize for the quality of some of the pics. Will get a better camera in the future.
Update; Corrected the size of the needles. I got confused with the amount which was about 6 to a pack to the size which is about 18. Sorry about that. ;)
Step 1: Template
Step 2: Trace Them.
Step 3: Start Threading.
Wind the yarn around the doughnut till you can’t push the needle though the middle any more.
Step 4: Cutting.
Step 5: Tie It.
Step 6: Trim and Tidy Up
Note: Cut the long string if your going to use it as a cat toy, keep the string if its going to be for clothingapplications est.
Step 7: Tips
To make the doughnut template you can use a compass for perfect circles but I just like to use a fish food container for the outer circle and the inner I use the one of the opening for fingers of my nail scissors.
Enjoy and have fun. :)