The old adage of measure twice cut once is good advice. I have a tendency to measure twice and cut a lot of times (in certain circumstances it’s easier to cut a little oversized and slowly creep up on the final size with a series of small cuts). In the photo below is the other way I frequently measure twice. In this case I was trying to find the center point of a board. The board was a hair bigger than 34 7/8. Dividing 34 7/8 in half to get 17 7/16 isn’t too difficult. The issue is that “a hair” is definitely not a standard unit of measurement. So I could just mark 17 7/16 and then just move the mark a half a hair to the right and hope that I find that center point, or I can try a different approach to the measure twice adage. In this case I just measured 17 7/16 from one side and made a mark. Then I did the same thing once again but measured from the other side. The center point is right between the two marks.