As the nights get cooler and closer to freezing, make sure you disconnect any outside hoses from your frost-proof outside faucets.
If you don't have frostproof outside faucets, consider getting them installed. If that's not an option, be sure to turn off water to all outside faucets and drain back the pipes to prevent freezing and cracking of the water lines.
For any vacation homes, make sure you get them winterized properly which includes winterizing your water heater.
Most importantly, when leaving your house for any period of time, make sure your heat is turned up to at least 55 degrees - this will prevent your plumbing system from freezing, which is absolutely no fun.
From everyone at Top Tier, Happy Fall!