How to make yoyo string

ok ive been making yoyo string but it never seems to come out good. ive watched xelas tutorial but it dosnt help me ,much i want to make string good for slacks and whips.can anyone help on how to make good string

Ok, what kind of thread are you using?
like, what brand (coats and clark, serger, guutermen) and type (cotton, nylon, poly, etc.)