Sometimes, people have life problems that can be entirely solved by doing one thing. (doing X made my life 0.1% better, PERMANENTLY!) These are not things like "This TAP made me exercise more frequently", but rather like "moving my scale into my doorway made me weigh myself more, causing me to exercise more frequently" - a one-shot solution that makes a reasonable amount of progress in solving a problem.
I've found that I've had a couple of life problems that I couldn't solve because I didn't know what the solution was, not because it was hard to solve - once I thought of the solution, implementation was not that difficult. I'm looking to collect various one-shot solutions to problems to expand my solution space, as well as potentially find solutions to problems that I didn't realize I had.
Please only put one problem-solution pair per answer.
Haven't quite reached the 100% resolved/full-payoff state yet but I once had a doctor firmly tell a family member to (paraphrased) not settle for a partial improvement and https://www.lesswrong.com/posts/fhEPnveFhb9tmd7Pe/use-the-try-harder-luke. I notice that when I apply that seriously to my health problems, entire swaths of the problem space vanish. I can't say that I'm 100% fixed though because my doctors and I are still digging around in the much-reduced problem space.
If you require something that's fully resolved or has definite results, then I'd say: