What tricks do you use to get cheap flights?

I want travel to south korea next month the cheapest flights tickets is around 1K$ with etihad air
is there anyways to get a discount or a coupon anything like that?

Keep in mind that the best trick is to earn more money. In the mean time, after playing with google flights, try these:

https://skiplagged.com
http://www.airconcierge.com

and if you don't mind paying a fee for someone else to find a deal for you: https://www.flystein.com