Should I cut my boards to size before or after I plane them flat and square?
We usually cut boards to length before planing. Whether you cut it to width depends on the amount of spare width you have. If the stock is a lot wider than you need, then rip it to rough width. You may want to leave a little material on to plane off later is the board isn’t very flat. This reduces the amount of planing to just the wood that you need. If it is close to width, then you can go straight to planing it flat and remove the the excess width as the last process.