80% and go: lose the desire to be perfect. If you can get to perfect the first time, you’re probably not dreaming big enough. Give it 80%, get it out there, and get ready for feedback. It’s coming. It’s okay. Use it. Learn from it. That’s how you’ll get to 100%.
I've always known that perfection is nearly impossible to achieve. Having said that, I have never started a project with the goal of achieving less than perfection.
Although this list of 12 pieces of advice is fairly well-known, you may find a few tidbits to inspire your next adventure.