I'm not AJ, but that's never stopped me from butting in before so . . .
It is hard to find anything definitive, in writing, about drawing trendlines properly. I thought I was drawing them correctly until LG and Shack on S.I. straightened me out, and I totally agree that sloppy trendlines makes for sloppy trading. In addition to AJ's opinion, perhaps LG would be kind enough to post some rules if you ask him nicely.