Instead of trying to fit a pencil into a tight space to make a cutting mark, use this little tool.
Answer Marking knife
A marking knife is usually about the size of a paring knife, but it allows the user to indicate where you need to place cuts. It can be used in smaller spots and often without too much movement of the wood, so the accuracy is precise.
Asked by Jennifer Sinclair · Last updated 5 years ago · 1.5M views · SOURCE