1)Subtractive EQ
It is always best to begin with subtractive EQ before you start boosting things and adding more thigs to deal with. Here are general guidelines or areas of focus. I generally follow the rule of five cuts for every boost. And use a digital EQ for more precise cuts
i. High pass filter at 20hz as the stuff below this frequency is generally not helpful
ii. Do a wide cut at 150-300hz to reduce muddiness and make room for the body of other instruments like the snare and guitar
iii. Do A wide Cut at 700-900hz to remove boxiness and make room for some of the grit in the bass
iv. Small cuts at 300-600hz to catch resonances
v. Lastly add a low pass filter at 8khz to remove hiss and noise
2) Additive EQ. Only if more work is needed after the cuts. Additive EQ is best done with an analog emulation of a transistor model plugin such as an API or a Neve. I generally focus in these areas
i. 50-80hz. Find the sweet spot and boost 2-5db.
ii.Cut the corresponding frequency in bass instrument
iii. Boost between 2-4khz for more drum
beater hit. Especially in songs with a lot of double bass
iv. For more brilliant and open kickdrum boost at 5-8khz(for slower
songs with less kick
v. Consider a dynamic EQ to do boosts in these areas as to not conflict with the bass