Believe it or not, scheduling my first thing of the day is meditation. Just 10 minutes. But it clears my mind.
Organizing is key. I will sometimes work with an overwhelmed client and notice that big messy desk. It can get out of hand. The time spent organizing is well-spent.
I use and old fashioned white board in my office. In busy season, all of my client's names go on it, so I can track where they are at in the year-end recordkeeping process. In this time of year (the slow time), I use it for inspirational quotes.
Lastly, my final tip is when it fells like you need a break, take one! A walk break in nature can do a body good. I love to take my dogs out and get away from my desk.