If you are just starting out using EQ, you might be overwhelmed by the possibilities to change the sound of your music. And you might say: “Yeah, let’s boost the 200 Hz because, hey, it sounds massive! Then let’s boost at 12000 Hz for clarity, and hm, boosting the 1000 Hz range actually gives some definition as well, so let’s do that too. Can’t hurt to do all of it, can it”
Yes, it can and it will. If you do, you probably end up with a mix that has neither weight nor clarity nor definition, because the tricky thing to understand is: EQ settings are relative and they might cancel each other out.
EQ is all about balance and relative volume. Put differently: Boosting the low end is the same as decreasing all frequencies but the low end. This means that changes you make in one frequency range are only as effective as compared to the changes you make in other frequency ranges. Increase all frequency ranges and your mix won’t change at all, just the overall volume will.
My approach: I try not to over-EQ my mix. I focus on deficiencies that I find during listening and repair them one after the other. I try to stay away from the idea of tweaking every frequency range until it sounds perfect.