24 Hour Comics Day can be quite the intimidating challenge, especially if you haven't done it before. Because Nathan Vargas and I had tried it before and failed, we started thinking hard about how to succeed - and I in particular started thinking about timing: how to break down your hours, how long you typically take breaks, and so on.
To keep myself on track, I started writing down panel timings as I was working, an almost unconscious decision that soon turned into a policy. As a result, I produced a nearly complete timeline of events of a successful 24 Hour Comics Day.
Everyone's method will be different, and this may not apply to you. But it shows at least ONE successful approach: preparing ahead, bringing good food, other refreshments and adequate supplies, getting planning done early, keeping each page tight, noticing that you're falling behind, finding faster ways to do things, taking breaks to stay energized - and never, never, never giving up.