I'd repeated too many times how I tweak my picture so here goes the SHORT version!
1. you KNOW a good picture (XG85/G70 at BEST setup in my case) to reference
2. you KNOW what picture looks BEST to you
3. you see the out-of-the-box picture and know what it's lacking
4. you try ALL the adjustment combinations to get the best possible picture while watching TONS of familiar clips to check/adjust black level, bright level, shadow detail, white layer, resolution, color, flesh tone, video noise, and all kinds of weird artifacts!
5. if the resulting picture is still not good enough, change something, screen, DVD player, cable, different filters, video processor etc and repeat step 4 again!
6. you just can't tweak anymore, then sit back and enjoy movies or get a new projector and start all over again.
I always envy those just put in the AVIA, check the bright/contrast and all is done. Living with a projector is not that simple for me.