My quick tuning tips:
1. start with the eq flat.
2. tune by ear to preferred sound, or as close as possible.
3. use an RTA to see if/where any significant spikes or holes are in the response and attempt to smooth these out.*
* if smoothing these out degrades the sound (may happen trying to fill a hole), then return to your previous settings. After all, you are listening to the system, not the RTA.
It also really helps to have the proper tools (read: CD's), just as with any other project.
