Use Extra Caution at the Start
Even when you've lined up properly, crowds at the starts can be a real headache. I've seen a lot of falls, as runners stumble trying to pass slower runners, get jostled by the crowds, or trip over a water bottle or piece of clothing that someone discarded at the start. When you line up at a race start, make sure that you don't get distracted by the excitement of the race. Pay close attention to other runners, and be on the lookout for discarded items. Avoid the temptation to jump up on a curb to get around slower runners -- that can also lead to falls.