When loading the boat on your trailer, distribute weight evenly from side to side and lengthwise. This may require redistributing equipment, fuel, and water onboard the boat to achieve the right balance.
Both the tow vehicle and trailer should be nearly parallel to the ground. Check the tongue weight to make sure you are not overloading the hitch; it should weigh about ten percent of the all-up trailer weight. (For example, if the boat and trailer weigh 5,000 pounds, there should be 500 pounds of tongue weight.)
Always secure the boat to the trailer with ratchet straps and ensure the trailer winch strap is attached to the bow eye.
A towed boat adds weight to the overall vehicle, so allow more time for stopping. Avoid sudden turns, starts, or stops that can affect trailer stability. Engage low gear when driving downhill.
Make sure your trailer lights are working, and use them even in daylight.
Before you start out, always perform a walk-around inspection of the trailer. A prudent rule of thumb is to check it again after 1, 10, and 100 miles of driving, in case a strap has come loose.
Carry a spare tire that fits your trailer, a grease gun, a lug wrench that fits the tires, and a tire gauge.

By following these simple guidelines you should find that towing your boat is uneventful and gets you where you're going safely.