I think you hit the nail on the head dude
I could tell you to high-pass, low-pass, multiband compress or what the fuck ever, but until you sit and fuck with an EQ and get a feel for what doing certain things will do to your tracks, it's all for null, because your actual understanding of how an EQ operates at your fingertips is what sets you apart from a kid with some waves plugins.
These are all things you'd discover yourself in time if you just sat and fucked about for a bit longer rather than just asking, and there's nothing wrong with asking and getting advice for settings, as long as you understand why such settings are used in certain circumstances rather than just blindly dialling in someone's settings then it's all good.
But anyway. I high pass overheads at 500hz and room mics at 200hz. I don't low pass either, maybe make a few cuts here and there depending on the mix.
And as far as whether high-passing shit is the way to do it, it's not THE way, it's just one way. It's like the difference between two stylish coats or some shit. They're both awesome as fuck, just different. So yeah, go ahead and fuck with multiband on the low end if it gets you good results (cos at the end of the day, if it sounds good it doesn't matter how you got there) but I'm just gonna high-pass shit personally.