Easiest thing to do.
Learn how you're system sounds, and then mix.
Burn said mix you seem to be happy with and play it in EVERY SINGLE THING IMAGINABLE!
And then, when you are finished with that, write down what you think needs to be done and then have your fun.
Easier than above:
Listen to your favorite pro-tunes and adjust the way you like it as far as bass presence.
Done.
EDIT: It'd cost you about $200 bucks. The ELC can be free, the mic will run you at least 100 for something decent to do the thing and the ROOM... have no idea. THe bass trap is really like 20 bucks or so. NO idea.
Basically, my ideas work better, I have a sub (and crappy monitors, but I digress) and my mixes (with the exception of the one I recently subbed) have all been nice and full sounding. Its really a matter of knowing how much bass is too much. Try mixing without your sub, or with it halfway and hten turn it up
Lots of ways to ensure you are in the sex(ily mixed) zone.