For every (EQ) action there is an equal and opposite (EQ) reaction

For example, if you add too much to the 2 kHz EQ band, eventually anything will sound thin and harsh. If you compensate by adding some 100 Hz to warm it up, you’ll end up with “scooped mids” and the sound will be thin and lack body. So you add some 500 and suddenly you’re back where you started, but it all sounds a bit processed and un-natural.

So I’ll finish with a final rule of thumb for you:

Less is more !

- and an outstanding resource, to an interactive frequency chart with even more rules of thumb and suggestions for the best EQ band to use eachinstrument. I don’t agree with all of them, but as Joe said in his video, there are no rules in audio – use your ears !