Porters at the airport and bellmen at hotels $1 US per bag.
Housekeeping $5 US per bed daily. Extra $10 for laundry depending on hotel rules. And and extra $20 per week to our main housekeeper. I do the daily tip because you might not get the same person every day.
Security gets $20 a week and I also try to befriend the gardener and slip him a $20 on top of any acquisitions he may make for me.
Wait staff gets anywhere from 10% to 25% based on service just like here in the states, although I tend to be more generous in Jamaica.
Airport and excursion drivers 20% and taxi men an extra route rate per person.
The key to all of this is besides and more important than your money is your attention. Remember names and greet them so. Engage them in conversation and get to know them. Friendship is priceless.