Cleaning and waxing your boat may gain you a few seconds over the length of a race. If you are an excellent skipper in a highly competitive one design fleet those seconds may be critical.

In very light/shifty conditions, getting into the right wind can make a difference on the order of tens of minutes. Boat handling (sail trim, weight placement, clean mark rounding) can make a difference on the order of minutes.

That being said, a few second lead can turn into a few minute lead if you can get to the first mark before the pack does. Nothing nicer than looking back at the mark and seeing all of your competitors trying to round at the same time in virtually no wind. And there's nothing worse than having that few minute lead turn back into a few second lead as the wind fills in from behind.