Cheap flight tickets
 

Hi, ckecked flight prices on OneTravel.com, FlightPapa.com and Skyscanner.com, can you recommend anymore? Thanks

I personally would not book with 3rd party sites. They can sometimes be useful when searching for flights but final booking is usually best through the airline's website. If anything goes wrong (delays, cancellation, whatever) and you'll have to deal through the 3rd party.

Use GF to find flights: Google Flights - Find Cheap Flight Options & Track Prices

After you select the flights you want you will see a list of links where you can by the ticket.

Like this:
One way to Singapore | Google Flights

(the airline website price is $8091, so book with them even tho the price is slightly lower elsewhere)

I used to use Skyscanner for Europe. It always gave me the best rates. You can also check for flights at the specific airline websites. Sometimes they offer good deals!

Look into flying award tic to your destination and buying a ticket for the return. That worked for me when one way Tokyo to LAX was $1600. Biz class

Unfortunately United doubled the miles needed for biz class on May 1 by surprise. Luckily I booked on April 30

There are a couple of boards on Flyertalk where the wonks (guilty as charged) spot good deals from the airlines. Make sure you're up on your airline and airport codes, e.g. DL SEA-AMS RT.

Mileage Run Deals - FlyerTalk Forums (Economy)
Premium Fare Deals - FlyerTalk Forums

There are lots of newsletters you can subscribe to that track good airfare deals. Going, Thrifty Traveler, Matt's Flights, etc. Start by signing up for their free tier.