Make sure it is well pegged and staked. Wind can play havoc with poorly pitched marquees. You will need at least one person to be permanently at the rego table and who is not playing. Remember, they have to handle late arrivals, media, photos, recording scores, time caps, defusing bombs, delivering babies, not to mention drinking all the beer in the eskies. Basically it's a full time job.
Food Try to make sure there is always food and drink available.
Making rolls takes a long time, but is good karma. A possible alternative is to supply all the ingredients, but let people put together their own. They would have sold better if we had had a lunch break. The most recent fad has been to try and include as much as possible in the cost of the tournament. As a result, we've taken to buying trays of rolls from Subway and supplying them 'free'.