How to fly cheap to the Philippines
Many people consider Philippines as an expensive destination in matter of the flight cost. Yes, the cost of the flight can exceed the planned budget and actually it is the most expensive part of your trip if you will choose this archipelagic country as your holiday destination. However there are still ways how to get there for a very affordable price from almost any place on the Earth.
If you are based in Europe and planning your trip to Philippines, the best friend for flight hunting will be the Google flights search. Direct flights from European capitals are expensive and served mostly by the leading airliners like British Airways, Philippine Airlines, Lufthansa, Etihad, Emirates, etc. So if you are looking for direct flight you are unlikely going to save on your trip. On the other hand if you are fine with short stop in Kuala Lumpur or Singapore, your flight can cost you less than a half of price of direct flight. Those 2 mentioned destinations belong to main connecting airports in Asia and there are hundreds of flights scheduled from Europe every day. The cheapest flight I ever seen was $220 from Paris to Kuala Lumpur and once you are there you can easily get flight to Manila or Cebu for $50. The low cost airliners providing flight services to Philippines are AirAsia Philippines or Cebu Pacific Air. They both have promo offers quite often. An advice for flying with them is to not book food, extra luggage if you don't need to, and do not reserve seat, you will get it assigned anyway, oterwise price will grow up fast. That will leave you at less than $300 one way to the Philippines. The way back can be the same or slightly different. The main point is to check what days are the cheapest. Weekends are usually most expensive but if you can fly on Tuesday or Wednesday, you can get it much cheaper.
I live in Australia and there are few options to fly from Sydney. There are direct flights from Sydney to Manila provided by Quantas, Virgin Australia, Philippine Airlines, Cebu Pacific Air and some other ariliners. Your bet is Cebu Pacific Air. I flew with them for AU$ 250 both ways :). They have very often promos for flights from Sydney to Manila or from Manila to Sydney but never both ways same time. So my recommendation is to buy the one way flight few months before and then wait for the price drop of the return way flight. That is how I was doing it in last two years and it always worked. They consider Christmas as a big opportunity to rob people who are travelling to spend yuletide time with their families and they dramatically increase their prices, that happened last christmas too, so I was searching for other alternative ways how to get to the Philippines cheaper. I discovered another pretty cheap routes. It is possible to get flight from Sydney to Singapore operated by Scoot or Sydney to Kuala Lumpur operated by AirAsia for as low as AU$140 and from there again, I got a cheap flight operated by AirAsia Philippines for as low as AU$ 50. The one way for less than AU$ 200 which is not bad for flight that takes over 8 hours. With Cebu Pacific Air better wear hoodie and long pants. Otherwise when you will be freezing they will offer you their blanket for AU$13. I suspect they keep the aircon on the plane on low temperature exactly for the purpose of increasing sale of their blankets.
I don't have any experience with flying from North America to the Philippines, however I am sure that Google flights will help you to find a good price for your flight. There is a range of cheap flights from Hong Kong or Incheon to Manila or Cebu operated by Cebu Pacific Air and AirAsia Philippines so once you manage to get there you can book really cheap way further to the islands.
If you really want to save a lot of money on your flight, you have to search and combine the routes. 3 or 4 hours longer flight is surely worth of consideration when you can save few hundred bucks, which you can spend different way. And believe me in Philippines there is many ways how to spend it and it have much higher value than in North America, Europe or Australia.