A straight answer for your product instead of a month spent preparing for the wrong day.
Most guides in this category are called 'How to rank #1 on Product Hunt'. That is the wrong first question. The leaderboard is now routinely topped by companies that need no promotion, the old hunter boost has been retired, and the ranking weighs discussion depth over raw upvote count. So the real question is whether the day is worth your month.
The first gallery image carries the entire pitch. If your product only makes sense after a five-minute explanation, the format is working against you.
You need eight to twelve people who will write specific comments about their own use case on the day. Not friends posting congratulations. If you cannot name them, you are not ready.
The badge and the dofollow link from a high-authority domain last forever. The traffic spike lasts a day. If you want the former, launch. If you are counting on the latter, temper it.
No working product, no community, or a niche buyer who has never opened the site: those launches land flat and burn the one first launch you get. The weekly leaderboards are a better first move.