I do a lot of open valleys here with 'w' flashing, they seem to shed the conifer needles better. I was cutting into a roof to tie in an addition and noticed something I hadn't seen before on the existing valleys elsewhere on the roof. The previous roofer had run a row of shingles all the way up the valley 3" from the 'w' before putting even the starters on. Then he'd shingled like anyone would with the exception that he hadn't cut the valley angle on the shingles adjacent to the valley, simply started with a square end that met the valley at the 3" mark. Relying on the first row up the valley to dump the water. He'd also started from that end so on this pitch he had about a 6" offset each course. This sure saves some cutting, what do you guys think? Rich.