Most of my Peruvian friend tip only about five Soles depending upon how they feel. And that amount of a tip it's not based upon the amount of the ticket. An expensive meal that costs 300 soles often generates a small tip of five or ten soles.
Last year I went to a friend's birthday party at a chicken restaurant and when I paid for my and my partner's dinner I added a little extra about 20 soles and said loud enough for everyone to hear here's a little something extra as a tip. The service had really been outstanding and I was hoping that the other people might think, "okay let's give a small tip to this and waitress," who waited on about 20 of us.
As we were getting up to leave I noticed that the waitress appeared to be very angry , and sure enough someone else at the table had pocketed the extra 20 that I paid so that he would end up paying less. The waitress didn't get a single centimo. I had known that could happen but had hoped it would not. From now on if I'm with a group of people and want to tip the waitress I'll give it to her on the side.
Oh well what can you say. In Spanish there's a saying, "a la tierra que fueres haz lo que vieres", the Spanish version of When in Rome do as the Romans do.
Professional, bilingual writer at your service.