I used to always be confused about whom I should tip and who much I should tip them. Plus, I had a hard time doing math in my head, so I often couldn't figure out exactly how much was appropriate even when I knew the percentage that I was supposed to tip.
My darling husband taught me how to quickly do the math in my head for percentages, but I still didn't know who exactly was supposed to get that 15%.
I had charts that explained in detail each person who would get a tip, how much, etc., but I didn't have time to memorize an entire list of individuals and corresponding numbers, so I made my own chart and broke it down into easy-to-remember categories.
See the Chart
http://www.kristensguide.com/Etiquette/tipping.asp