Americans have the tendency to tip. A. L.O.T.
In Asia, tipping is not standard. Nor required. Large institutions that cater to Westerners (not just foreigners but specifically Westerners) often automatically add an 10% service charge, after which you are not expected to even leave the change. In some countries, people get offended when tipped. Yes, I am speaking of Japan.
In Thailand, we round up. To the next five for small charges. In restaurants, regardless of the size of the bill, be it 10,000 Thai baht or 100 baht, we tip the person, not the bill. So usually 20-60 baht. The tips generally get pooled together at the end of the day and split evenly across the staff.
So, tipping in the States felt excessive. It used to be 10-15%. I’ve noticed it uptick to the point many people start at 20%. Whoa. What do you start with?