It's already been mentioned but its worth repeating, tying GOOD knots. I don't care if I have re-tie a knot three times, I'm going to do it until it looks perfect. Properly seated, decent sized tag end, etc. It gives me peace of mind when I hear my drag start to sing.
Also, the use of quality terminal tackle. Solid swivles,
snaps, split rings, and at least 4X hooks. It makes absolutely no sense to spend $600 on a reel, $300 on a rod, and then decide to cheap out on the most important components.