I been having my credit card for 2 years. All I do is use up to 10% then pay off nearly the monthly bill, but will always leave $10 on the balance, so it can always look like that I consistently owe them. My score shot up over 100 points. I also heard if you make two payments within the same month then your score will increase faster too
It works, just be safe
this is what I did, paid two payments in May/ start of June.