I agree that braided line is the #1 improvement during my fishing years. I also agree that Breakaway clips and breathable waders have been huge improvements. A few others might be.
Handheld GPS for finding holes/structure on the beach at night that were located during the day (beats putting that washed up lobster pot buoy on the beach to mark the spot).
Very realistic sand eel imitations (and other realistic plastics such as Storm Wild-Eyes).
Fluorocarbon line.
Butterfly jigging (though that's a boat gig).
Sit on Top (SOT) kayaks rigged for fishing.
