Most of the important stuff has already been posted.
The best EQ is the volume fader
Paint in broad strokes. You don't need hard Q and a gazillion band splits everywhere. My general rule is to do half the adjustment I think it needs and let the brain adjust
Avoid graphic interfaces, they tend to make us overdo things (brain sees squiggly curve and thinks more=more)
Avoid EQ charts like the plague
Adding bass or air during writing/mixing usually takes you down a slippery slope
An adjustment on the stock Ableton EQ will sound pretty different from the same adjustment in an elysia musEq, Pultec etc.