I'm another one who doesn't like tipping, but I understand that some people's pay is based on it. I either tip for good service or I don't tip at all, meaning I don't short-tip for mediocre or bad service.
I'm still tipping 15% for good service. 20% may be the standard now in some areas, but IMO that's a lot. I know the system isn't fair. They should be paid a decent wage. It might mean businesses would charge more to cover that, but maybe not. If they charge too much, people will vote with their pocketbooks and just not buy from them.
One area I deal with a lot is hotel tipping. I tip housekeeping for a good job, but that does mean for cleaning (vacuuming and actually washing the tub), not just for making a bed. I tip more for sensitivity to my needs. So if I moved the Kleenex and wastebasket to my bedside table and they empty the wastebasket and leave it there, that gets more tip than if they move both things back to the bathroom.
I don't tip hotel maintenance for fixing something it's the hotel's responsibility to maintain, such as keeping the a/c working. Once I asked to have the air vents cleaned because they were literally spewing bits of black stuff onto the bed. The guy did a thorough job on the vents, then vacuumed the floor by the vent and brought new bedding. Him I was going to tip, but he said maintenance guys were some of the best-paid staff in the hotel and shouldn't be tipped at all. I ended up writing a letter to the management about his excellent service instead. OTOH, I've had others come up to check the a/c fan, be unable to fix it, and still expect a tip for coming at all. Not happening. At that point, I expect a new room or a free night for no fan.
I don't tip front desk people normally, and I try to keep requests from becoming a "tipping opportunity." So if I need an extra roll of toilet paper, I'll go down to the desk to get it and ignore offers to deliver it to my room. Am I cheap? Hotels cost a lot, and I'm not about to pay more than the toilet paper costs just for them to walk it over to me. And really, am I expected to tip when I ask for directions? It seems some hotels expect that.
One area where I probably am cheap is valet parking. If I choose to use it, I'll tip. If it's required to have my car valet parked, no tip, because I'm having to comply with hotel or restaurant rules. I don't like other people parking my car and only rarely would ever choose to do it, so I'm sure not going to tip for something I don't want to do.