The Week Before Your 5K
There is no workout you can do in the last week prior to your 5K that will enhance your performance. Therefore, make the final week prior to the big race an easy one with light workouts (continue to follow either of the mileage buildup charts). Make one of the two days prior to the event a complete leg rest day.
Don't try anything radically new or different in the weeks before your 5K. Don't try a new diet; don't try new shoes. Taper your mileage at an easy pace, get adequate rest, and prepare yourself mentally for the big day.
Don't break with your training schedule or try anything radically different the week before your race either. For example, one of the most frequent mistakes that comes back to haunt the unsuspecting runner, whether it be in a short event or in a marathon, is to run in new shoes purchased the day before the race.
It takes at least a few training runs for new shoes to get broken in. Wearing new shoes even a few days before the race can cause a variety of problems, such as blisters and foot discomfort, which affects your performance in the race.
Lay out everything you need (apparel, shoes, etc.) the evening before the race to save yourself time, stress, and aggravation in the morning. You don't want to be halfway to the race site and realize you've forgotten something, especially if you have to help others get ready to go with you. It's important to have everything you need arranged ahead of time.