The big risk so far with this pending storm is flooding, especially in low lying areas. The models are predicting 6" to 10" of rain along the coast. Tropical storm Allison taught us that these low power yet stagnant storms can produce enormous amounts of water.
During the storm this weekend, stay in place. Don't drive - especially in lower vehicles. And if you do, DO NOT enter water and assume you can make it. The greatest way to reduce loss is to avoid it in the first place. Either go back and wait or go around if there is a path.
Don't make the mistake of assuming you can traverse the water without it entering your car, killing the motor or electronics, or sweeping you off the road. Even a slow current can lift a car off its wheels. And without power, you cannot open your windows and water pressure will prevent you from opening your doors.
As for property, this storm is not presently expected to build such wind intensity that it necessitates boarding up windows. But it would have been nice to remove the excess growth from trees adjacent to your home. Tree damage is the most common thing to first occur. What is important is the idea of force created by the difference of 90 to 100 to 110 mph wind can be much greater than the 10 mph difference implies.
Take care and check out these resources:
Last Minute Check List
National Weather Service Tropical Cyclone Page
City of Houston, Emergency Preparedness
The difference of Fortified Home Construction