Frequent travelers between US and Korea, How do you do it??

I apologize if this has been answered elsewhere, but I'm looking to find out how people who do frequent back and forth between the US and Korea manage to afford it. I make a decent amount of money per year, and I know plane tickets aren't free, but I'm trying to lower costs as much as possible. I'm looking into going to Korea for medical checks/treatments because the US is so impossible, so I'd likely need to go at least once a year for a while. At this point I've never been, but have been looking into going for vacation, but with medical stuff I'm thinking a more extensive trip/more than one trip might be in order.

How do you keep costs down when you have to travel back and forth for a job or visiting family? My initial searches for plane tickets were very expensive, but I'm assuming I don't know the tips and tricks since I know a lot of people who make less than me go 1-2 times every year.

Any advice would be greatly appreciated!