First thing is to remain calm in order to keep the child calm. The more upset the get the worse it gets. Much like anything else you need to follow your instincts. When I am chocking sometimes someone doing some clapping on my back helps, sometimes rubbinng my back helps and sometimes just letting me ride it out helps. No matter what works the most important thing IMHO is to not freak because that will add anxiety to the whole situation. Easy to say I know.......thats the best I have for you!