While working the spar and using your flip line run your hand around each side of the flip just before making the cut. If it is too big take a couple of steps around to make sure your flip line is not hung on a stub. Checking to see exactly where your line is and know exactly where you are making your cut.Always have a climb line set lower in case somehow you do cut through the flip line. This only takes seconds once you become fluent with it and it can save your life.
Now that's a good one! Something I was taught to do and it's second nature now.