You know what to do at 12:01am and what to ignore for the next sixteen hours.
The day itself is mostly discipline. Everything you can control happens in the first four hours and in the comment thread.
Placement is heavily influenced by the first few hours. Launching later in the day leaves you competing against products with a head start you cannot recover.
The story of why you built it, what it does not do yet, and one specific question you want feedback on. It sets the tone for every comment under it.
Reply depth is ranked. A thread with real back-and-forth outperforms one with more upvotes and no conversation.
Claim the badge, add it to your site, and update your other listings with it. That is the asset that outlives the traffic.