1) You could get a 3rd party aftercooler for your GPU. Though considering you have a midrange GPU, it probably won't matter.
2) Install more case fans if your case allows it (usually the bigger ones are quieter and push or pull more air). Also you could set up a proper push/pull system in your case if it's not already set like that. For example - if you have a space for 1-2 fans in front of your case, you could set those to intake air, and if you have a similar number of fans on the side or the back - you could get it to expel air.
3) Re-wire the inside of your PC case for better airflow.
4) You could even mod your case for better air flow, say for example modding a fan on top of your case to expel hot air.