Tipping is a simple subject: some establishments already incorporate a "Service Charge" (often designated by "SC" on machine printed receipts) or you tip independently.  If you intend to tip and there is no service charge multiply your total bill (minus any VAT by 10%. If a service charge is present, please remember the wait staff may not see any of that extra charge. Use your own discretion on how much you will tip. (As in other countries the owners can be very unfair to their staff.) Some restaurants and bars that do not already incorporate a service charge may state this clearly on the bill as "SC not included". Overall, tipping is usually expected in tourist areas, but don't feel pressured to leave a tip if the service wasn't good. 

The Philippines is traditionally a non tipping culture and so if there is no service charge a tip is not necessary but welcome.  Tipping is not common among the local population.

Locals often round up the taxi fare, so if the fare is 88 pesos, they will give 100 to the taxi driver.