If they are wire bead then I wouldn't think they would get much easier to be fair. You could always waggle the tyre side to side a little in sections as you run it through your hands. Not sure if it'll work but cant hurt trying.
If feasible how about a dab of grease on the rim just before you get the last bit on.(obviously wiping off afterwards) something like that would be easy enough to carry in a very small tube/pot when touring. Actually you can buy a relatively small container of talc and it isn't a bad thing to have when on tour for those areas that get shall we say a little sweaty when doing longer rides