Clacton - the biggest one-way system:
Entering the big one-way system: if you've just come from the test centre direction you need to give way as you enter. If the examiner wants you to right at the end of this section, you may be asked to go directly into the right hand lane. If so, go straight across into the lane, not into the left to then change later. Remember not to indicate to go right at the end until you've passed the side-road on the right. (below)
In the next section of the big one way system: Left hand lane for London; right hand lane for straight ahead (photo below): if you have to change lanes it needs to be after the hatched area, and before the crossing.
The big one-way system on the way back to the test centre (picture below). You may be asked to pull up on the left near to the green sign. When you pull away it must be clear in both lanes behind, as someone in the right hand lane may be intending to pull in in-front of you once they've got past (silver car). Make sure that whenever you pull away that you don't inconvenience anyone; even if that means waiting for ages.
The video below shows a few circuits of the one way system: