Spend class review time wisely. Ask what type of assessment will be given. Once you know this, you can study and focus on this type of assessment. Study regularly prior to the assessment, not just the night before. Help build your memory bank.
Some students like to use a web with question-words or categories to build their recall.
Work with them on a regular basis. Take a series of deep breaths to relax. Remind yourself that you are prepared for this assessment and will do the best job that you can. Make a trip to the restroom and drink some water before the assessment. Sharpen your pencils beforehand.