The House

Ventilation is key. The ability to open windows, ideally with blocking mechanism to allow you to open the window enough for fresh air, a window that locks, and has screens. 

Water and moisture are the enemy. Keep them away and down the drain. Use gutters outside, have many down spouts, keep them free and clear so water can move, otherwise in the winter the water will freeze, then water backs up under the roof and floods down the wall and ceiling. So they are useful, but if not taken care of properly they cause more harm. 

Learn how to do all the work that doesn't require a license, especially if you care about attention to details. But, sometimes it's easier to pay someone. Don't pay for anything upfront, or buy and store the materials at the house yourself, and pay for the install promptly AFTER completion. 

Cover the outside faucet covers and blow the water out of the sprinkler houses and especially underground sprinkler lines. 

Keep the crawl space dry and ventilated. Keep mouse traps along the walls.