This tends to be a favourite of learner drivers once they know how. It follows a simple formula and is easy once you know how. Like with the other parking exercises, don't neglect the set up or think too far ahead.
There are several ways to go about the reverse bay parking exercise. I find to the right easier as you can look out of your window at the lines for longer. At Avonmouth test centre, all the bays are on your right, so it might be worth practising this direction more for test day if this is your centre for the exam.
We call this the three bay methos as you're going to need three bays to get in. You'll use the furthest line of the bays of the three, bay 1, as a reference point. You'll skip bay number 2 entirely and land up in bay three, the closest one to you currently. See diagram below to help visualise.
First off, try to get central down the aisle. Or have at least have the width of a car between you and the tops of the bays. Being too close wont see you able to come round to being parallel with the lines of the bay in time. And too wide could see you swing into the cars parked on the other side of the aisle.
Then, once straight, stop alongside the further of the three bays and have this line run across the top of your thigh. You need to use your imagination a little here. Envision this line continuing out and into the cockpit. This is sometimes different for different people as we all sit in slightly different places. But some where between the steering wheel and lap is right.
Once here, stop and get ready for step 2.
Make sure you POM. So into reverse, observe everywhere around you as danger could be anywhere. Also making sure your hands are in the correct place. If you're reversing to the right, high right hand and vice versa the other way.
As soon as it's safe, slowly release some brake and immediately turn full lock towards the bay. So right for right and left for left.
The car will swing backwards towards the bay. Look over your right shoulder to begin with seeing how well you are doing in relation to the third bays lines. The fish eye lens of you mirror can take over that job when further back.
Once half way in, stop. Get everything under control and check the left door mirror. Hopefully you'll now be able to see both sets of lines on both mirrors, which will help when it comes to straightening up.
Lots of little movements and stops can help get perfectly straight before the straightening up part. Once that's done, look over your left shoulder out the rear window and come back the remaining distance.
To finish off it's handbrake and neutral and you're done.