Finished taxes this year. How to reduce the refund/owing?

So I finished my taxes this year. Got a 1.5k refund from federal, owed ~800 to NYS, and getting ~500 back from NJ (non resident return).

What can I do to lower the amount of refund/owed? I file Single with 1 exemption (myself).

I went to the info on my employer's site and turns out I was claiming 0 for exemptions so I changed it to 1 which should help a bit.

Federal return was pretty simple, just income from W2, the standard deduction for filing single, 4000 on line 42 for exemptions, and that's pretty much it. Is there anything I can do to try to lower the refund/owed?