Invest in an impact-resistant garage door (these are indicated by a special sticker), or reinforce your existing door at minimal cost by nailing planks of plywood or steel to the door's back. A garage is often the primary point where wind enters and damages a home, and garage doors are often made from flimsy materials.
Reinforce your home by installing storm-resistant windows, especially if severe storms are a regular part of life in your region. If you live in calmer areas, you can consider cheaper options such as installing storm shutters, which you can nail into your window frames.
Keep a close eye on the trees in your yard to make sure they are disease-free, strong and upright. If a tree seems to be rotting, dead or starting to lean to one side, you should consider having the tree cut down or removed entirely. A diseased or weak tree can mean major damage to your home in the event of a severe storm, whether by falling into the house itself or by tree branches breaking off and flying into windows.
Check the ground around your foundation. To prevent water from entering your home during severe rainstorms or even hurricanes, it's important that the ground slopes down from around the foundation. If the ground surrounding your home slopes toward your foundation, that is a problem. You can fix this issue easily yourself---simply fill the downward sloping area with some dirt and plant grass seed, elevating your lawn around your home and keeping water out of your basement (or other floors, should the entering water rise).