Two of my friends attended bartending school during college and then accepted jobs at a local chain Mexican restaurant. The bartending school had much better placement for graduates than our university. Their bar was an upstairs setup at a place out in the suburbs. They had to wear polo shirts and black pants every day, but thankfully the job required no flair. The most popular drink at their bar was a pre-mixed frozen margarita dispensed from a huge glowing machine behind their bar. My friends were in charge of mixing the margaritas that would go into this machine, and after a couple weeks at the restaurant, they began adding an extra couple gallons of water to the mixture and skimming the profits off those extra margaritas for their tip jar. It was a pretty clever move and one that's apparently very popular in bars, though I don't think it was covered in bar tending school.