If have never done it before, consider that the characters seem to come in waves. If you arrive and there are no characters in your area, then get your food immediately and prepare. They seem to leave about ten minute gaps between the character visits to allow you time to get up and pick some food. Also, if for some reason you miss a character or you are being ignored, politely find one of the coordinators and inform them that you have missed characters in your area. Sometimes it gets busy and areas get missed but from my experience they are more than happy to make sure a character comes by. It might take a little while due to breaks. I have witnessed a few families who left in anger because they didn't see all the characters.