One thing that you can do to raise your CreditKarma score now is let only one card report a $2 balance. A utilization between 1-4% is most optimal when talking about FICO scoring. Like chrisj500 said, 1% is ideal. But CreditKarma's scoring should be almost identical in this case since utilization is a simple calculation.

Why $2? A $1 balance will be seen as 1% util regardless of the amount of credit you have. If you have $100,000 of available credit and let $1 report, your util will be 1% (not 0.00001%). The reason you should let at least $2 report is credit card companies forgive debt with a balance <= $1.99, meaning you're not obligated to pay it back so it won't report. Discover for example will write it off when a new statement hits. For most it's $0.99. Citi won't even forgive $0.01. It's a variable amount between banks.

Look at the statement dates for all your cards and let a $2 balance report on the card that has a statement anniversary coming soonest. The sooner the better. If a new statement gets posted 3-4 days from now (leaving time for a new transaction to post), you'll be able to get another CreditKarma update next week with the updated util. That's if that particular credit card company updates credit reports on the statement date, but most do.

I bet you'll get a higher FAKO if you get your util to 1%. Grade should become an A.