I have an important interview tomorrow afternoon, what steps can i take to ensure my mind and body are in top shape?

Practice & sleep: Ask a friend for help w/interview questions. Practice answering questions. Search internet for (un)common ones & how best to answer them. Practice & then practice some more until you're comfortable. Get plenty of rest tonight. No booze (or sleeping meds) to avoid hangover. Eat light meal for breakfast & lunch (don't want to be hungry (or sleepy from food)). Brush your teeth after lunch. You'll be.