Looking for some help on digging lug

. Decided recently to start digging my own bait, so having first checked the section in Fox Guide to Sea Angling and watching a few guys dig off Bull Island....I gets my buckets, fork etc and off I goes, I mean...................how hard can it be !!!! An hour and a half later, I'm knackered and 6 worms to show for it all (and only 3 were big lug)

I wont bother with the detail of the following session but suffice to say it didn't get any better

I dug on both occasions off the Bull Wall at Dollymount, in fairness a popular spot as we all know...........
but jesus the lug musta seen me comin. Some guys I had watched previously were digging round holes and they looked reasonably deep.....but they were getting worms !!!
Any general information as to how I should proceed would be very very much appreciated. Should I dig round holes or trench, how deep, in front of cast, behind cast etc etc. Everything I've read says to dig for blacks at the waters edge on the full ebb or just as it turns but every time I go out to Dollymount the diggers are always way up at or near the bridge and the tides miles out

On the subject of.............what about digging Rag ? The spirits willing, the forks brand new but the auld back wont stand up to much more without something to show for it lol. My thanks again for any help from the members who I have found to be a mine of knowledge and information and always more than willing to help.......poor eijeets like me lol, thanks