Carrying cash and an ATM card is best; credit cards are also widely accepted.
Bartenders Usually not expected.
Delivery persons A small bill.
Hotel cleaning staff A few pesos per day (only at upscale hotels).
Hotel porters A small bill.
Restaurant servers 10%; 15% for fine restaurants with great service.
Taxi drivers No tip unless they help with luggage; many people round up to nearest peso.
Tour guides 10% to 15%