Measurement

Measurement in home repairs needs to be precise. I don't do precision. I do creative, wacky, original, fun.  Even accurate is a challenge and certainly never exact.
I measure 3x and cut wrong. I am also a little shaky when I cut a "straight" line with tools such as reciprocating or circular saws. Apparently, getting the knack requires regular use and as previously stated I generally avoid power tools. Due to all these constraints, I compensate by cutting things slightly larger than needed. The rationale is as follows: if cut too short, a piece of lumber, metal or roofing material may become useless, while a slightly longer section can be wedged in (caveman style) or whittled down by hand!

Levels are fun. but I often get so carried away that I forget to use them. Plumb bobs are really cool but I mainly just play with them during breaks in the action. I got pretty good at using chalk lines when a friend helped me re-roof our first house in the late 80's. In the backyard of our current domicile I made a four posted "Love Arbor" with bench for my lady. Years later, while a buddy was helping me build the tree-house, he took a level to that structure. He then categorically stated there was nary a level surface anywhere on it!