A mixture of all of them. But with paper tickets I mostly got them either to debit my credit card remotely (having sent them a scan of it) (e.g. CX in TPE), and/or to take a swipe when I picked up the ticket just before the first flight (e.g. BA & AA in CAI). For AA MNL it is either wire transfer or get there to make the purchase (my wife was able to do the latter).