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, but don't feel pressured to leave a tip if the service wasn't good.

(Please note that when this article was first written, the exchange rate was USD$1.00=~PHP52.00.  As of OCT 2012, the current exchange rate is USD$1.00 = PHP41.00) It shouldn't matter what the exchange rate is; you are charged in PHP and you will tip in PHP.

Just like almost anywhere else in the world, wait staff appreciate a reasonable tip. Many of the wait staff in places foreigners visit are aware of what a good tip is and will try to offer you the quality of service deserving a reasonable tip. They will not "appreciate whatever tip you give".  Don't be a "Cheap Charlie", provide your server with an appropriate tip.