Hey, I'm sharing one of my favorite tools. A Veritas Saddle Square. Actually I have two in different sizes. This is the large size for marking 2x4 and 4x4 (shown on 4x4 here). One of those tools that makes woodworking a pleasure.



They're great for continuing lines from side to side. And even side to opposite side.
Works really well when the board has a rounded edge or some wane where the edge is not really sharp and square but the two adjacent faces are square to...