I've never had any luck with conventional moustraps.
Glue traps work ok but they tend to get covered with dirt/leaves/bugs and lose their effectiveness within a few weeks.
I tried one of those electronic gizmos that claims to scare them away by 'creating an acoustically hostile environent'

otfl and I'm not terribly impressed. I put it right in front of a glue trap and the next day there was a mouse in the trap.
I made a mousetrap out of an old laundry soap container, a beer can and a dowel and I caught 5 mice in 2 weeks with it.
-cut the top off the container
-poke 2 holes near the top (for the dowel)
-drink beer
-punch a hole in the bottom of the can so that can fits loosely over the dowel
-slide dowel through one side of container, slip on the beer can, slide dowel through other side of container.
-smear some peanut butter on the can
-pour an inch or two of water into container (antifreeze in the winter)
Mice will go after the peanut butter and fall into the container. I put this outside the garage, last thing I want to do is encourage them to come inside.