First seal up any openings that they can get through. Steel wool is great, because they won't chew through it. Here's a link with more information for you:
Steel wool bits stuffed in every crack with a pencil.
Also, try spraying peppermint oil and lemongrass oil on your foundation's exterior, as high as possible.
Get rid of bird feeders/food that attracts mice (pet foods, grass seed, etc., which should only be stored in tight fitting, weatherproof metal containers.
Place numerous scented dryer sheets in sheds, stored vehicles ( inside the vehicle, under the vehicle, and under the hood).
Remove stacked logs near your home. Cut down tall vegetation. Remove dead leaf litter. Keep mulch away from home's foundation.
Use binoculars to check for potential entry points at high locations of your home's exterior, then have them sealed.
Check external dryer vent for lint and remove it (mice will use it for a nest).
Check attic and add hardware cloth to gable vents, if warranted.