I have come across the opposite problem lately. When I was working in the restaurants we tended to tip over generously. But when we go out we usually get the "hook up" and end up tipping way too much. I don't go out as often anymore. And as I am now a single mom, with a steady paycheck, I find it harder to give the 50-100% tip. My brother & sisters are still in the industry, and now I look like a cheap old fart! I still tip over 20% on what the bill would have been had we been charged for everything (on drinks I usually put in a little more, normally a dollar a drink).
I have started just putting in that amount, and let the rest of the group be responsible for their own overtipping. But it still is a pain, and I feel cheap.