Here's a useful addition to the 3 foot ruler with the inset level...a string level. I suspect that this is "old hat" to most of you experienced folks, but why not share anyway? I'm finding this quite useful for winding along my branchline as it curves its way through the as yet unfinished mountains. These are cheap, and I even got a set that included a grade indicator as well. I'm not sure if this is worthy of the "Tips And Tricks" thread, so I've put it here.