A bath and grooming for one of our border collies usually runs around $60-$70. I generally tip $15 or $20. If the dog is really dirty or otherwise more difficult fhan usual, I’ll tip a little more.
For me it’s not about percentages, but rather time spent vs wage. For example, my haircut needs are simple, and I usually just go to a local barber who charges around 15-$20. I know they are getting minimum wage or below, so if it takes half an hour I’ll actually tip as much as the cut, or $15. If the person does a rush job or I don’t much like the result, it might be $5.
If I go to a hair salon and they spend the same amount of time and charge me $60, the tip doesn’t change. So in the first case I might tip 100%, and in the second maybe 20%, but the amount of tip per hour dossn’t change.
Likewise, back in the day my friends and I were known to frequent coffee houses for hours at a time, with the waitress having to serve us free refills all that time. So I’d get a bill for $5 for coffee, and leave a $20 tip to represent the fact that she had to do as much work for us as she would have if we’d have ordered a complete meal. If I was with a cheapskate who tried to tip 15% of a $5 bill after tying up a table for four hours, I’d tip even more to make up for it. And I’d stop inviting that person to our coffee and gab session unless they ponied up properly.
Instead of fixed percentages, use the golden rule. Put yourself in the other person’s shoes and think about what’s reasonable for the specific situation. Did you make them do extra work? Did they go the extra mile on their own?
This is where I like to do charity as well. If I see someone working hard for low pay, I’m much more likely to give them a really large tip. I can afford it, and they are struggling yet trying their best. I prefer to help people that way rather than give donations to large NGO’s where I have no control how it’s spent and who gers it.