Give the urge somewhere else to go
When you see your dog start, interrupt calmly and hand them a frozen Kong or a lick mat (freeze it for 2 hours or overnight so it lasts), or a chew. Build in a sniff walk or a puzzle feeder each day.
Licking is self soothing. Itch, boredom and stress all feed the same loop, and the licking then irritates the skin, which makes it itch more. Never scold; it adds stress and pushes the licking to when you are not watching. A tired dog licks less.
If your dog is fixated on one spot, this is the moment for the Anti Itch Spray. Two or three pumps hydrate the skin they keep going back to, and that takes the pull out of it.
When At your dog's usual itchy times, often evenings and right before bed.

