ATMs dispensing US currency are easily found in all but the smallest of places. Credit and debit cards are widely accepted and you can use them in all but the most casual of food trucks and stalls. Watch for mandatory fees at upscale hotels and resorts.
Generally, you tip in Puerto Rico as you would on the US mainland.
Bars $1 per drink.
Buffets Tip staff 10% to 20% if they are serving you your drinks.
Luggage attendants $1 to $2 per bag for anyone who helps with your luggage, whether it's a skycap, shuttle driver, bellhop etc.
Pool/beach attendants $1 to $2 for each service rendered.
Restaurants 15% to 20% of the bill.
Taxis 15% of the fare.