After selecting your exam you'll be presented with Proctortrack's Best Practices:

Ensure your face is clearly visible - Anything that obscures your face can cause your test to be flagged for violation. This includes hair, sunglasses and hats. Reading glasses are acceptable, however.

No Bathroom Breaks - If you need to use the bathroom, you should use it before the test. Once the blue frame appears you may not leave the camera's view.

Create the proper lighting - You must be in a consistently well-lit room, with as plain a background as possible. Changes in lighting can cause your test to be flagged for violation. 

Turn off noise making devices - Your test environment must be free from outside noise. Turn off all sound-emitting devices completely; mobile phones on vibrate still emit detectable sound.

Stay within the webcam's frame- You must be in the frame of your webcam at all times. Even stretching, looking away, or leaning down to pick up your pencil could cause you to be flagged for violation.

Use a private testing area - You must be alone at a desk and chair so that you are sitting upright during the test. If other people are around you, you could be disqualified.