In assembling the rod, use the tip from the slot next to the butt section. Then move the tip you're NOT using into that (now empty) slot next to the butt section.

After fishing, put the tip you used into the empty tip slot. Then, all you have to do is get in the habit of always using the tip next to the butt section, and moving the spare tip into the vacancy.

For me, this is a lot easier than ID'ing the section, tying knots, etc.