I trap and/or hand pick excessive snails from my tanks on a regular basis and destroy them.
An alternative to manual removal of snails is to start stocking snail predators in the tank. There're various fish that will do that, but I'm a big fan of assassin snails, since they're less likely to develop your standard fish diseases.
I've read that they eat about 1 snail a day, but it's hard to give an exact number on how many you should get since you're shooting for a balanced ecosystem.
I can tell you what happened in my 20L, though. I stocked it with a pond snail that hitchhiked it's way into my tank, about 20 starter MTS and 3 assassins. One assassin went MIA and hasn't been seen since, the other two have doubled in size and are laying eggs and my trumpet snails pretty much are out of sight, out of mind. The pond snail population boomed and now is down to about a half-dozen visible pond snails and there are lots and lots of snail egg cases around the tank.
I eventually ended up taking about 4 - 6 of my largest MTS out to seed a new tank, but that was the only time I ever removed a snail from it.
I'm potentially going to have a half dozen assassin babies, so I may end up having to restock my 20 so that the assassins continue to have food and breed.
I've read reports of assassins opportunistically feeding on shrimp, but I haven't found anything definitive, and generally assassins prefer slower moving food (ie snails) anyway.
Hope that helps!