Make sure the monitoring you use with your editing system is as good as possible (neutral and balanced) and set up optimally. It is the filter through which everything passes and will effect all the choices you make, for better or worse. Listen on as many different systems as possible, and on different days, before deciding which choices are good and which are not. Usually that is the only way to work with confidence when using monitoring setups that ordinary mortals can afford and/or live with.
As for what to do, EQ is the most useful and powerful tool, and effects the aspect of sound for which we are most sensitive. Put your primary manipulation efforts there.
But always remember that your choices (EQ or otherwise) can only ever be as good as what you can hear, even if you have a good grasp on what you are doing.