The key to EQing multiple tracks is to contain each track in its own space to keep your tracks from competing for the same frequencies. It's important to remember to do this all in moderation if you want a natural sound, but the rules are always different depending on the genre and the sound you're going for.
Here's a loop I put together using drums and bass guitar.
It's generally a better idea to EQ each drum microphone separately, but for the sake of this lesson, I've already combined them.
The first problem that really stands out to me is that the bass is too damn bassy, especially at the low end. This area should already be occupied by the kick, which is too weak.
Now I've cut the low end (100 and lower) off of the bass guitar and boosted it on my drum track. This way the kick will dominate the low bass. Then I boosted an area around 240 for the bass guitar's higher bass sound and lowered it on the drum track. I also boosted 2k or so on the bass track to make the fret sounds louder and to give it more attack. Then I finished with some minor adjustments to the drums to make them sound a little clearer. Here is the final result.
Keep in mind that the loops were kind of shitty to begin with, and you can only polish a piece of shit so much before it smears. I hope you got something out of this little demonstration anyway.