Obviously focus, but don’t let the fact of it being a driving test faze you. Treat it like a normal drive, which to be honest it is. If you get a talkative examiner, depending on how confident you are, you could even talk to them to relax you. I talked to my examiner throughout because that made me feel like i was just driving normally.You can, if you really want, put music on the radio during the exam. The more you think of that exam, the more pressure it’s going to put.
You’ll want to ensure that you thoroughly know the test area, and any tricky roundabouts or junctions around it. Make sure that you can plan way in advance before reaching a junction, cos you don’t want to hit a tricky junction and make a rash decision. Go around the hard junctions or multi lane roundabouts with a close person or instructor.
Also, just drive slower on approach to junctions. Give yourself plenty of time to choose the right lane, and ensure your lane discipline is good.
Good luck and hope u do well 😉