<prompt> Human: Im 21 and my credit scores just barely almost in the excellent range and I wanna try and get it to the highest score I can. Just moved into an apartment and financed a car Ive made two payments on those so far both on time and plan to keep it that way. I have savings in the bank for emergencies. Ive been seeing ads for credit cards that offer rewards for using it, are any of those any good? Would it be smart to use one to pay my bills and just pay it right back. Are the rewards for using a credit card bigger than the possible costs?  <response>: No, they are really THAT good, if you are a responsible person. 