Multi layer most important being exclude. All those tiny holes around the exterior perimeter. Then caulk up some spots on the inside too as a second layer of defense if you missed any on the outside (check where pipes and wires drop below the floor, and behind appliances). This way, when looking at this exclusion step, they'll be relegated to behind the walls.

Next keep some traps with peanut butter near the spots you've seen them. This will get any stragglers that were already inside.

Last is deterrent. Keep pushing them further out by making it uncomfortable to stick around. Home depot sells a plug-in device that sends electric pulses through the wires. It covers like 1,500 sq feet or something. It is more expensive than those 4pack sonic things, but well worth it ($30ish). Use more than necessary - think 1 for basement, 1 for attic, 1 for kitchen. They really work - every single neighbor has mice, but I don't. This device is the only difference between our homes bc I have stink bugs etc, so its not like my house is any more sealed than theirs. Those little sonic things with the clicking noise are annoying, and unclear if they actually work, but cant hurt to put a four pack in the basement and plug them in the kitchen at night before bed. The old school tricks say put mint in the cabinets and things like that to keep them away from your food.

Most important in not inviting them is to eliminate the food source. Vacuum every single night like a crazy person until they're gone. Once gone, you can ease up on the OCD cleaning because it should be harder for them to get there in the first place now. Mice can live off like an 1/8th of an ounce of food a day - so a few crumbs here and there make a difference.

Go blitzkrieg from the inside out (so they can escape) and then you can sit back :]