a few hints:

dig for the shrimp near the water line, at low tide or at the incoming tide. It seems like the water forces the shrimp to be closer to the surface. I found that I need to dig deeper (and hence more effort) if I am high on the beach and the water is way farther away lower on the beach

about 6 years ago, I dug some shrimp on the north willapa bay area. All I needed was a pitch fork to scoop up the sand and the shrimpies were exposed with a single scoop. Again, close to the water line as the water rose on the incoming tide. Or, I suppose it could have been that particular location in Willapa Bay or some anomaly of nature when the shrimpies were so close to the surface.