Keep an eye on Secret Flying - they post international specials every day on Facebook, and you can sign up for daily email alerts specific to your continent/area. That's how I got return flights from Canada to Asia for $500!
I recently booked my flight to Saskatoon. after running through many flight comparisons I booked using cheapticket.in . I used https://www.skyscanner.co.in/ and at that time CheapTickets was the one giving the lowest for the route and flight I chose. one point to note the site that offers lowest fare can vary at times.
here are the points in favor of CheapTickets.in
- the main point they have the filter of choosing refundable tickets and the time I booked I wanted to have some flexibility and they have that option straight away
- smooth transaction, quickly (5mins) got all PNR and complete itinerary
a word of caution: please double check the name you are typing, possible take a screenshot once you enter the traveler details. because strangely I ended up seeing typo with a letter missing after booking the ticket.