This article is specifically about submitting a cocktail seminar to Tales of the Cocktail, but several points in the list of seventeen items apply to a wide variety of events, regardless of topic or venue.
Also, it has been said many times by many people and in many ways- one of the best tips for getting your proposal accepted at any event is to follow the rules. Really, read the rules/guidelines for submission, and follow them. Also, submit early. Most event reviewers are volunteers and do it in their spare time, something which gets scarce when the deadline approaches. Submit early and you’re more likely to get non-bloodshot eyes looking at your paper.