In philosophy, a razor is a principle or rule of thumb that allows one to eliminate or shave off unlikely explanations for a phenomenon, or avoid unnecessary actions. Occam’s Razor is one such well-known heuristic. I had written about it a few years back. You can read it here.
When it comes to reasoning, elimination is a more robust strategy than adding. Sherlock Holmes famously said, “Once you eliminate the impossible, whatever remains, no matter how improbable, must be the truth.”
Shaving off the untrue guarantees to leave you with the most probable version of the truth. From that logic, investigating any phenomenon using razor like thumb rules is a very efficient way of better thinking. Better thinking leads to better judgment and decision making. Better judgment and decision making result in better action.