Some of my favorite business (and life) advice of all time comes from Warren Buffett's business partner, Charlie Munger:
Do what works and keep doing it. That's the fundamental algorithm of life—REPEAT WHAT WORKS.
This is especially great advice for early-stage founders. We're prone to spinning our wheels trying a million different things, and we often find it hard to cut the cruft and focus on one thing (project, feature, use-case, etc.) that's showing promise.
What are you working on that you should probably double down on, or already have?