Update: That weird job in the old theater basement taught me a seam trick
I was installing carpet in the basement of the Majestic Theater downtown, a space they were turning into a lounge. The floor had these wild, uneven dips from old plumbing. I was about to cut a seam right over a low spot, which would have looked terrible. The building manager, an old stagehand, saw me and said, 'Kid, shift your seam line six inches onto the high side and stretch from there.' I did, and the seam just vanished into the flat area. Has anyone else had a weird tip save them on a really uneven subfloor?