Well, many types of snail-eating fish would not be a good idea to introduce to certain types of tanks, so it depends. Dwarf puffers eat snails, as do loaches, but you have to be careful adding these fish, especially the puffers. Many loaches get very large so it depends upon the size of the tank.
You can try sinking a lettuce leaf or a celery stalk at the bottom and the next morning there are likely to be quite a few snails eating it, at which point you remove it and the snails. Do this every day for a while until you don't get any more snails. Often if you cut back on feeding your fish the snail population will reduce due to lack of extra food. Try to avoid using a snail-removing chemical in the water, if you can help it.
Good luck - this is a common, tricky problem and there is no foolproof way to handle it, unfortunately.