People who work for tips earn their livelihoods at your mercy. A tip is not a tool to coerce the server or hairstylist to indulge your whims; it’s simply the currency of service jobs. An adequate job requires a standard tip, and outstanding service is rewarded with a bigger one. Don’t think of a tip as a supplemental cost; it is as integral to your purchase as the tax you pay. This is something you will really embrace once you have the opportunity to slave away in a tip-earning position. Doing that job will teach you a genuine respect for service workers, and to tip generously.