Before starting on a trip, practice turning, stopping and backing up in an area away from other traffic (such as a deserted shopping center parking lot) to gain experience in handling the extra weight and length of the trailer. Take enough time to get the feel of the vehicle/trailer combination under a variety of situations.
Skillful backing requires practice. Back up slowly with an assistant acting as a guide and watching for obstructions. Use both rear view mirrors. Place your hand at the bottom of the steering wheel and move it in the direction you want the rear of the trailer to swing. Make small corrections, instead of exaggerated ones, as a slight movement of the steering wheel will result in a much larger movement of the rear of the trailer.
Allow considerable more room for stopping when a trailer is attached to the vehicle. If you have a manual brake controller, lead with the trailer brakes when approaching a stop. Trailer brakes are also handy for correcting side sway. Just touch them for a moment without using your vehicle brakes and the trailer should settle down and track straight again.
To assist in obtaining good handling with the car/trailer combination, it is important that the trailer tongue load be maintained at approximately 10-15% of the loaded trailer weight.
Check everything before starting out on the road, then stop after you've traveled about 50 miles (80 km) and double-check the trailer hitch and electrical connections to make sure everything is still OK. Listen for sounds like chains dragging on the ground (indicating that a safety chain has come loose) and check your rear view mirrors frequently to make sure the trailer is still there and tracking properly. Check the trailer wheel lug nuts to make sure they're tight and never attempt to tow the trailer with a space saver spare installed on the car.
Remember that a car/trailer combination is more sensitive to cross winds and slow down when crossing bridges or wide open expanses in gusty wind conditions. Exceeding the speed limit while towing a trailer is not only illegal, it is foolhardy and invites disaster. A strong gust of wind can send a speeding car/trailer combination out of control.
Because the trailer wheels are closer than the towing vehicle wheels to the inside of a turn, drive slightly beyond the normal turning point when negotiating a sharp turn at a corner. Allow extra distance for passing other vehicles and downshift if necessary for better acceleration. Allow at least the equivalent of one vehicle and trailer length combined for each 10 mph of road speed.
Finally, remember to check the height of the loaded car/trailer, allowing for luggage racks, antenna, etc. mounted on the roof and take note of low bridges or parking garage clearances.