Max the volume pot, since that has to drive the rest of your signal chain. On a J bass, you can have one volume at less than max, to achieve a different tone, but on a P, you need to really crank it, so that the fullness of the tone comes through. You then temper it a bit, with your tone pot, and if that does not suit your tastes, then your amp's EQ, or some other outboard EQ (or pedal preamp) might be your thing. I have come to swear by my VT Bass Deluxe for larger gigs, where I need a lot of tonal versatility.
Oh ok ok, I get ya'...
Thought it had to do with me installing the wrong type of pot, but i bought it as a "wiring kit"...I use a Sansamp PBDDI, so I'm covered. Thats why I read that a lot of folks max the volume out.

