Pamper Your Voice No matter your focus -- book, field, Court, announcements -- your voice is precious to you. Take care of it: drink fluids, use lozenges, perform voice training exercises and warm-ups. If your voice is not up to snuff, recruit help.
Get Sleep You will be among the first to be wake in the morning, and among the last to be done with the day's duties.
Clean and Maintain the Tabard This is a sign of respect for the people whose arms you will bear.
Know Your Court Obtain copies of ceremonies needed, discretely learn how people prefer to hear their names pronounced (it will vary, and Court is not the place to correct someone), recruit enough people to share the load. Will there be a sign herald?
Know Your Tournament Recruit people to staff list fields. Ensure they know the basic procession and introduction cues and patter.
Know Your Books Bring the set of books you expect to need, more if you make use of them. Bring appropriate ink pens and markers, and copies of the current submission forms (not old versions -- those are cause for administrative return). Bring charged phones and laptops if you can, and a power strip.
Know Your Heralds Know your local and regional heralds and you can ask them for help.