Flights
In my blog post Getting There I explained how I've traveled abroad on the cheap. If you have a specific location and timeframe you must travel, then I recommend using Skyscanner and Kayak to look up your flight options. The most useful travel hacking tool both sites offer is the Explore feature. If you have a bucket list of locations and a general idea of a month or week when you want to travel, filter the search by this information and you'll discover your third choice may be significantly cheaper than your first, but you're still making headway on that bucket list. Use the linked images to navigate these sites, but do not use them to purchase right away.
You've entered the world of travel hacking, so it's time to start banking every reward and loyalty point. I'll search for cheaper flights on one search engine and make my purchase with Expedia or a credit card travel booking site, so I can get the points multiplier or free nights. Once you've found a specific flight, use the customer service chat features to have the representative find and match the flight cost if you're unable. The image below links to Expedia as an affiliate link because I believe in transparency for the programs I use myself.