For any new guitar I get, or pickup change, I've always started with the pickup VERY low in the guitar, as low as 3/4" away from the strings if I can, and just go from there. I'll play it for a while, clean, dirty, palm mutes and so on. Then I'll start raising it ever so slightly and repeat the playing every time I adjust it. This kinda gives me an idea of what the "sweep" (for lack of better term) of the pickup is like. When I was using JB's in my Eclipse, I started using them close to the strings because that where the most output seemed to come from. Later I found that I liked them very low and far away from the strings. Sure they lost some of their output and gain, but they gained alot more clarity and articulation when I did that. At that point I started experimenting with lower output pickups and found out those were more to my liking. But just starting from the bottom and working my way up is how i've always done it. Passive, active, dont matter. Stating low and going all the way up, and backing it back down again to where I thought it sounded the best for what I was playing.