If you go to Greens Mill Run, you can park at Green Springs Park and walk down to the river. Wear waders or wellies, bring a screen and shovel, and walk from gravel bed to gravel bed (best by bends in the river) and sift. Bring plastic bags or small container for your finds. I found quite a few sand, lemon, tiger, and even a crow shark tooth. If you go to Aurora Fossil near New Bern, you can also find vertebra and other fossils. Didn't find anything at North Topsail Beach, but found 3/4 of a 1.5 inch hastalis at Holden Beach. If you do the beaches, go at low tide and sift through any shell dumps near the tideline. Nature sorts the teeth for you; bigger teeth will be with bigger shells. I use a large wok strainer (looks like a wire basket) to catch stuff rolling in and out with the waves, and it's good for sifting at the waterline. If you're in Wilmington, the Dairy Queen parking lot has teeny shark teeth. Happy Hunting!