When you go for a worm dont let your shadow fall over the worm, use a fairly firm piece of fish bait with out to many trailing edges. Maintain loose pressure between thumb and finger. When the swell washes over the worm wait for him to arch up his back between your fingers. Apply tension with fingers and here is the important bit Pump the worm as you are pulling him out this avoids the tug of war and your success rate will be much higher. If you get a skitish worm its best just to move on and try another. You will get him on a different day. I often use an old fish frame on a rope to excite other worms while I am chasing a different worm a few meters away. I once saw a guy catching them with his toes. smartarse.
Cheers Pueter