Is there a practice of tipping our guides?

Is there a practice of tipping our guides? If so, how much is usual for tipping guides? We will have three different guides during our 15 day tour.

Hell, Patricia,
Tipping is seen as a mark of appreciation for a job well done.  Of course you don't have to.  However, anything you do give will be much appreciated.   While guide and driver are concerned it's become a standard part of this culture, even though it may not be in your home country, and if people haven't been shopping then a small mark of appreciation goes a long way to helping the guide know if they've done a good job.

If you want to tip your guide to express your gratitude for the good service, we recommend 20 USD to your guide  and 10 USD to the driver per person for a trou part of 2 persons.