The key to travelling on a budget is planning ahead.
First, decide on a destination or activity. Then do your research. Which place is nearer? Which would require more travelling time? Which offers more amenities? Which offers more activities for everyone going on the trip with you? Which offers complimentary breakfasts or tickets to local parks/shows? Are there guided tours you can join?
Come up with your itinerary months ahead. You get the cheapest fares and best cruise deals when you book ahead of time, mainly because that's already assured income for the airline or cruise line. Consider travelling during the non-peak season too (say, Boracay is absolutely filled to bursting with people during the summer, so go on the leaner months. It's also quieter then and you can have more of the white sand to enjoy).
If you're after the experience and not really the accommodations, consider just getting a day tour of a resort instead of actually staying there. Plus, staying in transient homes may just give you a better feel of the local flavor.
Lastly, consider using the rewards points or miles collected in your credit card or Flyer card. It might just land you on Business class seats you normally wouldn't be able to afford.