It takes time but it does get better. For us it has taken about 6 months, we've had tears and tantrums (and that's just me) eldest (17) is now settled, youngest (14) still wants to go back to UK but think he is torn between UK and WA he likes the lifestyle to a degree but misses family and friends back home still. From before landing I had the I want to go back, don't want to be here/like it her etc., slowly that's easing off to about once/twice a week now lol! he is getting a circle of friends but still spends time on facebook/xbox talking to friends "back home" he's not keen on school system here but that's something else!!
Other half loves it and wouldn't go back for all the tea in china, for now we're trying to enjoy it as much as we can and take each day as it comes, but yes it does get better it just takes time