Tipping is highly recommended throughout your trip. Unfortunately, Cancun and its surrounding areas have a high poverty rate with some individuals earning less than $300 a month as their salary rate for working full time. A lot of these individuals within the tourism industry rely on tips for their livelihoods and the Mexican government doesn't help much. Everyone who services you in Cancun deserves some tip if they're serving you with honesty.
Below is my tipping guide which I've created for your reference. I recommend this as your minimum tipping base. You can choose to follow this as your minimum tips, go higher, or go lower if you wish. After all, tips aren't mandatory, but highly recommended.
Note: If you are not at an all-inclusive hotel, or you are at a restaurant/club/bar that's not all-inclusive, it is best to tip 10-20% of your bill. If you are at an all-inclusive hotel and are sitting down at a restaurant which has a "price" next to each menu item, it's still best to leave 10-20% of your bill as the prices are shown there as your tipping reference.
The reference below is assuming you're two people. We are assuming an average of $1 USD = $20 MXN (MXN = Pesos).
Poolside Service (Drinks) $1 - $2 per round of drinks ($20 - 40 MXN)
Poolside Service (Food) $5 for entire order ($100 MXN)
Bartenders at Bars $1 - 5 per drink ($10 - 100 MXN)
Lunch Service (No Prices Shown) $5 - $10 for full service ($100 - 200 MXN)
Dinner Service (No Prices Shown) $5 - $10 for full service ($100 - 200 MXN)
Lunch Service (Prices on Menu) 8% - 15% of total bill
Dinner Service (Prices on Menu) 10% - 18% of total bill
Poolside Assistance (chairs/umbrella) $5 for moving things around ($100 MXN)
Housekeeping (both day/night) $5 per day ($100 MXN)
Hotel Bellhop (luggage assistance) $5 for assistance ($100 MXN)
Driver carrying luggage (taxi/shuttle) $1 per luggage or $5 overall ($20 MXN or $100 MXN)
Room Service (any) $5 for delivery ($100 MXN)
Taxi/Uber/Shuttle $3 - $5 for trip ($60 - 100 MXN)
English Speaking Tour Guide: $3 per hour (pay at end) ($60 MXN)
Tour bus/shuttle/boat Driver: $5-10 at the end of the tour ($100 - 200 MXN)
There are different types of ways you can tip people throughout your stay. This is just a reference that I recommend you should use throughout your tip, but please tip whatever you're comfortable tipping. Don't overtip if you cannot afford it or if you aren't getting optimal service.
If you tip higher than the average of people around you, you're likely to get more attention from servers. Same is true when you tip less than average of people around you, you're likely to get less service.
Sometimes you can tip one high bill at the beginning of your service, for example during poolside, and you can tip smaller increments throughout the day for your service.
Sometimes you'll end up with "your own" server if you tip well and you'll be serviced by one person whom you'll grow to trust throughout your trip.