How to Control Which Side to Turn to in Flip Turn?

I have been practicing flip turn for some while. All my turns are to my right side. I intentionally try to turn to the left but mostly fail. However I have seen many other swimmers turn to their left most of the time. I was wondering what are the critical points that control which side to turn to? I guess mastering this will help me to get a better feeling and balance under the water. Do you also think so? Thanks!