We book with our line, but I also use a TA. I’m fussy on what airline I travel with, and also the route, so before it comes time to ticket, my TA and I have already selected the flights. Avalon has been great at booking them, at a better rate than we find. If I don’t extend pre or post, they provide transfers, but that’s not a problem. Once they ticket, I can select our seats and upgrade them if needed, all I have to do is go to airlines site, paying directly to them. We had our seats booked before our final payment last cruise, it felt weird paying for the seats before we paid for the flights. 😀
We fly next May, but I have already been looking at what is available.