Cut out a piece of foam or cardboard the color of the yarn you're going to use.
It should be about an inch circle with a small circle cut out of the middle and a cut going to the outside.

Wrap the yarn 10 times around your hand (give or take a few wraps depending on desired thickness.) You can also use multiple colors.

cut it off your hand and tie it in the middle with another piece of yarn.

Comb through it until it gets fuzzy and all the twists are gone. It will come apart a bit, but that's a good thing as this will give the ends a tapered look

Comb through on both sides all the way down to the knot.

Glue the mustache onto the bottom middle of the foam/cardboard piece.

Put on your mustache (yes, you have to put it in your nose) and style it. It can be bushy or sleek, it's all up to you!