Don't start. Nothing happens if nothing happens. How many times have you had an idea, then seen that idea in the wild a few years later. If you never start, you never win.
Create a product nobody wants. Just because you built it, doesn't mean they want it. Don't make something you think is cool. Make something someone else things is valuable. How do you know it is valuable? They pay for it. Don't ask people if they think it is a good idea or cool.
Stop before you ship. It takes longer than you think. Last 10% can take 90% of the time. Even if they project is 99% done, 0% of the value is delivered if you don't ship.
Pick a massive project that is super hard to finish. If you continue forever, you can finish huge projects, but small wins are motivating. Small projects that you can finish can build momentum.
Don't market it before, during, & after. Even if it is a great product that people want, if no one knows about it, it won't work. Successful marketing is just sharing valuable information with people who find it valuable.
Ht @amyhoy for the ideas.