First of all best of luck with the launch! I will suggest to make a tutorial or demo of your open source product and get the feedback. Also engage with PH community.
Looking forward to seeing your launch! As we will be launching for the first time ever on Product Hunt by end of this month, I researched some basic information, but other than that it's simply about building a great product.
The basics I researched:
- Tuesdays and Thursdays seem to work good for most companies
- Launching at 12:01 PM (PST) gives your product the chance to circulate on the platform for full 24 hours, which can result in a higher ranking
- Good screenshots and presentation slides that are appealing and communicate the benefits clearly are helping the people to understand your product better
- A short introduction video to your tool is great to hook people on your product page
A really good example is guidde. I found the tool on Product Hunt by coincidence, but it saved me so much time making nice how-to videos.
Best Regards,
Felix