Standards differ. There will always be big tippers and those who think that all inclusive means just that, ALL inclusive. But the people who serve you don’t make much, especially the lower-level servers and housekeeping, so a tip is always appreciated and, no matter how much or how little you tip, you will never get a frown that says “cheap ba$tard.”
A quiet “thank you” or “muchas gracias” with a $3 tip will be more appropriate than pulling a ten off a wad of bills and a loud “Here ya go!”
And there is nothing wrong with tipping in USD – dollars are universally appreciated and often used for savings, since the peso depreciates.
Oh, and housekeeping always appreciates a tip. Leaving $3-5 and a short note will usually get your clean, fluffy, white towels folded into amusing animal shapes.
In the past, I have gone to my US bank and bought $200 in ones and distributed them as appropriate. YMMV. Buen viaje!!