I got handed at $100 bill on Christmas Eve-Day when I worked at Sonic. I asked the dude three times if he was serious or not cause I couldn't believe it.

Worst tips were the bitches who ordered the 98 cent 44 ounce drinks and told me to "keep the change." Wanted to throw it at their stupid BMW SUVs as they were pulling away.

Also, as a barista, it pissed me the hell off when people would order four stupidly elaborate drinks and then rush off without leaving tips. Tip your barista, dammit!

I tip everyone, even if they didn't give me great service. I tip when I pick up to-go food. Usually the restaurant service is okay and not spectacular, but I don't think my server needs to polish my shoes in order to receive a tip.