If you are or have been a restaurant server, you most likely know that tips may make up 85-100% of a waiter’s earnings.

Your income depends not on simply showing up or clocking in, but on the quality of your service … right?

Research from tipping expert and Cornell professor Wm. Michael Lynn suggests otherwise.

Lynn has found that tips are only “weakly related to service quality,” and that the factors that really influence tips don’t necessarily involve better service.

In fact, there are at least 13 tricks that have been proven in studies to increase tips. Check them out:

In the chart above, from Lynn’s paper “Tip Levels And Service: An Update, Extension and Reconciliation,” he outlines the results from testing a variety of interactions with customers. While most of these are self-explanatory, note that all servers don’t need to don flower crowns: “Wearing flower in hair” may simply mean adding an accessory or flourish that sets you apart from other servers. Lynn does note that some of these techniques may not be suitable for more upscale establishments.

And of course, there is one other trick to getting higher tips that every good server knows: Sell more food.

Since customers should be tipping 15-20%, Lynn says that giving them a bigger bill may be the most effective way to get yourself a higher tip. When the restaurant is busy, he explains, it’s probably more lucrative to push pricey entrees and turn over tables, and when things are slow, you can take the time to add to the bill through appetizers and desserts.

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