Use honorifics or familial words. "Sir" and "Madame" can get you pretty far but also try to use the word "Po", which is a word of respect in the Philippines.
Be friendly. Filipinos are very friendly people, so being kind in return will help a lot. That goes for most countries, however.
Bring your sense of humor. Filipinos usually cope with humor. Taking time to laugh with them will earn you a genuine appreciation for the gesture.
Remember to say thank you.
Don't be shy, wave back. The locals love to wave. Waving back is a nice gesture.
Try out all the local food, its simple, fresh and surprising.
Don't be flashy. Try to be modest in the Philippines. Try to avoid wearing jewelry on the street and make sure to use your electronics in a safe environment. Otherwise you will be most likely be targeted by scammers and pickpockets.
Don't refuse food. Filipinos are a very hospitable bunch of people. If you are their guest they will most likely offer food, if you already ate maybe take something small.
Don't keep your wallet in your rear pocket.