
Reversing a trailer, like public speaking, is an activity keenly avoided by many people. However, like presenting a speech in front of strangers, following a few basic principles and plenty of practice should soon have you a lot more comfortable with the process.
In our experience, often backing large caravans into tight camping spots, it's best to take your time and not rush. Taking it slow allows for minor adjustments of the steering wheel before the trailer has the chance to head off in undesirable directions, or jack-knife, forcing you to drive forward and start all over again.

Patience is especially critical when you have to place the trailer in an exact spot while avoiding obstacles like kerbs, poles or overhanging branches. Taking it slow also allows you to keep an eye on the front of the tow vehicle, to avoid damage if swinging in from an angle.
Even when using a helper to guide the trailer into place, it's useful to stop and sometimes get out and reassess the situation before resuming. Of course, it's best to try and start with the car and trailer in a straight line, and use your mirrors so you can still see the nose of the car. If the trailer is smaller than the car, and can't easily be seen in the mirrors, enlist help.

If using your mirrors and you see too much trailer in one mirror, turn the wheel towards that mirror to straighten. Once you have the same amount of trailer in each mirror, you're heading straight back.
Like golf, trailer reversing can be viewed as a game of 'opposites'. The easiest trailers to tow – lightweight box trailers – are often the hardest to back in a straight line, while the most difficult to tow – long, heavy caravans – are often the easiest. This is because the longer drawbar and greater distance between towball and trailer axle helps reduce the inclination to jack-knife.

Also confusing to beginners is that unlike driving forward, the trailer will turn the opposite direction to the way you turn the wheel when going backwards.
Remember: turning the wheel to the right will make the trailer go left, and turning the wheel to the left will make the trailer go right.
Once on track ease the wheel back to centre to follow the trailer back to a straight line.
You tighten the wheel to tighten the turn but if you turn too far, you can jack-knife the trailer. If you sense this is about to happen, pull forward a little and try again.
And don't be afraid to turn your head and look through the side or rear windows, to get a better view of proceedings.

Of course, none of this makes much sense until you get out and practice, ideally in a big empty space on a weekend. This will help build confidence before facing the crowds at the local boat ramp or busy caravan park.
Use witches hats or cardboard boxes to avoid expensive hits, and if you have one, take your helper along to work on a suitable form of communication, incorporating hand signals, shouting or even two-way radios.
As far as self-education goes, there are some excellent Youtube videos (see below), or attend a professional towing course or buy one of the Reverse Mate kits to help learn the correct method.
If all else fails, you can try fitting an aftermarket reversing camera system to the back of your van for an extra pair of eyes. Or unhitch and attach a battery powered trailer mover to the drawbar, making it do all the work while you stand back with the remote control...