The fastest way to get in debt is having too many credit cards. Never have more than the amount you can safety pay regularly on time. In general, having credit cards and installment loans (and paying timely payments) will rebuild your credit scores. Someone with no credit cards, for example, tends to be higher risk than someone who has managed credit cards responsibly. One major factor in your credit score is how much revolving credit you have versus how much you’re actually using. The smaller that percentage is, the better it is for your credit rating. The optimum is 30 percent or lower. So to boost your score, “pay down your balances, and keep those balances low. If you have multiple credit card balances, consolidating them with a personal loan could help your score. Also any bills you currently pay, morgage, utilities etc. all goes to credit score so you want to pay those regularly as well. You want to keep your balances low on all fronts and if you have been managing credit for a short time, don't open a lot of new accounts too rapidly. New accounts will lower your average account age, which will have a larger effect on your scores if you don't have a lot of other credit information. Also, rapid account buildup can look risky if you are a new credit user.
Another way to raise credit score is to is to eliminate nuisance balances. Those are the small balances you have on a number of credit cards. The reason this strategy can boost your score is because one of the items your score considers is just how many of your cards have balances, that’s why charging $50 on one card and $30 on another instead of using the same card (preferably one with a good interest rate) can hurt your credit score. So, gather up all those credit cards with small balances and pay them off. Then select one or two go-to cards that you can use for everything. That way, you’re not polluting your credit report with a lot of balances.
But honestly, time builds credit. While I suggested a few ways, there really isn't an 'instant credit score hike' like there are no 'get rich quick' schemes. Just have patience and pay bills regularly. When it's time to get whatever you need the good credit for, you will have it.