It is too easy to just say EQ and compress. It isn't helpful to give wrong frequencies or even what some think are right ones either.
The "right" frequencies are in specific ranges, and I agree not around 55-70hz, but around 800hz isn't helpful either. I also agree side-chaining compression to duck the bass out for the kick is of little benefit for most types of music. Simple EQ and compression works better.
What really matters is the context of the song and what everything else is doing and in what ranges. You have to use your EQ to find the sweet spots for the kick and the bass, roll off the inaudible for both, notch out the mud on the bass where you want the kick to come through, and boost a bit on both where the sound is most round. The best way to do this is to take your EQ, and make huge sweeps with the node in your frequency ranges until you find the spots that either need boosting, notched out, or whatever. Once you find where they are, you can make the minor boosts and cuts. It just works faster that way.
It is helpful to make notes as you go along, because after you work out the kick and the bass, you have the rest of the drums and all the other instruments to deal with. Keep notes (pen and paper is still the most handy thing in mixing) of what is boosted and notched out as you eq all the other tracks to give them their space so you don't have too much competing with the same ranges.
When you compress, don't go for the squash on everything, just add enough to keep what falls below a minimum threshold from being too quiet, and maintain consistency of the instrument's level throughout, and do it for every instrument. It is only when you want to use compression to mangle transients of sounds to your desire does squashing for loudness become a factor, but that is a different thing entirely.
I have found that my best mixes have EQ on every track, and compression on about half of them. But likewise, I have both the EQ and compression on every track doing as little as possible, if you know what I mean.
If you work your way up from the drums, and keeping notes of what is going on where and in what frequency range, no matter how many or how few drum layers you have on your kick, it will always be heard no matter what, and no matter how loud or how soft you have the fader levels on everything else. The volume of the track fader is still where the most loudness/volume of every sound should occur in a mix, not the EQ or the compressor.
Otherwise, going crazy with the EQ and compressor on everything can destroy every reason why you used the drums and other instruments you wanted to use in your track together in the first place.
By the way, panning to use the whole stereo field goes a long way to help things get heard helps a lot too, and not every instrument needs to be recorded or bounced down to a stereo track either...especially drums, synth basslines, most leads, and other sampled or synthesized instruments that would be naturally recorded in mono were it a "real" instrument.
