Little neck clams are the most tender and flavourful, and they're the first clams you'll find, only 2-4" below the surface. If you don't find lots of clams in the first few forkfuls, move location either higher or lower on the beach. There's a sweet spot where they get the right balance of time underwater and out of water, but typically they're roughly halfway (vertically speaking) between high and low water marks.
Once you find clams, don't dig further down. If you keep digging down you'll get the larger but tougher butter and manilla clams. Better to keep digging wider and stay shallow. Don't keep anything smaller than a loonie, let those grow up for next year.
Best tool is a 3 prong garden fork, the type you use with one hand. Bring 2 buckets, one for collecting and one to hold clams you've washed off. Back at camp, do another rinse with fresh water and then cover them with fresh water. A handful of oatmeal will help to settle out fine grit from incomplete washing. If you're cooking them whole in shell with other ingredients, you have to be obsessive about cleaning, no one likes a gritty meal. Watch especially for empty shells filled with sand/mud but look like a good clam. I test every single one with a fingernail to make sure it's not a hand grenade.
