The embassy does NOT require applicants to submit BOOKED roundtrip flight tickets and hotel(s) before applying for a visa. But if in case you want some "peace of mind" and still want to book a hotel to show to the embassy, it's best to do it with Booking.com or Agoda.com. With them, you can reserve a hotel with NO pre-payment and you can even cancel the booking a day before your arrival with NO cancellation charges at all. For flights, you can get a flight RESERVATION from OneWayFly for a small fee of only Php 1,000~. I highly recommend them because they are fast, easy, and legitimate; plus, I have been using them for years for all of my visa applications! (Read here for more info).