1) If I'm cutting multiple strips or squares, or when squaring blocks, I put a strip of little blue painter's tape by the correct measurement. It help to find the right line for lining up on the second, third, etc ones.
2) The measured fabric is under the ruler and the extra is hanging smoothly from the side of the table.
3) Try not to drop a 60mm cutter on your hand. Did that this week.
4) Have fun!