The best thing you can do is get to the place early and then drive around the nearby neighborhood for 30 minutes. That way you can spot things that might trip you up - hidden bumps, one way streets, stop signs that are concealed, sudden and seemingly pointless drops in speed limits, etc.
Here are reasons my friends and family have failed (I passed on my first attempt)
1) My wife was driving 25 in a 25 mph zone. She saw a 30 mph sign far up the road and decided to speed up to 30 mph. Well legally it is 25 until you pass the sign. She failed.
2) My sister failed for doing a very common thing. You legally must stop BEFORE the crosswalk and stay stopped before it. She was turning left at a light. There were cars in the way so she stopped before the crosswalk. Then she inched her way forward (which I bet 99% of drivers illegally do) until she was stopped basically in the middle of the intersection. Then she turned left when she had the chance.
3) My good friend failed for driving in the oncoming traffic lane. Most of the turns in our town had a left turning lane when you want to turn left. All of them except a couple of intersections right next to the courthouse. He needed to turn left - so he assumed there was a left turning lane and pulled to the left. Well there wasn't - there were just two lanes - each going in opposite directions. You can imagine the horror on the tester's face.
#3 is an example of someone who needed to test drive the area.