Bounceback and denial
So a government loses office by only a few seats, and as they approach the next election they are convinced that a few carefully-targetted marginal seat campaigns and a forest of junkmail will enable them to return to office with a "now, where were we?".
People don't change governments lightly, and will give even a fair-to-middling government a second term. Any Premier/PM who sticks around beyond a year after losing office is kidding themselves (unless you have an extreme situation like the Nordmeyer budget) and their party should have the sense and the fortitude to struggle out from under their erstwhile leader's dead weight. Sometimes so-called sophisticated campaigning techniques just don't bloody work.
They won't work for Rob Kerin in South Australia and while Kerin's self-deception is understandable, that of his party isn't. Various anonymous sources in the SA Libs will come over all hissy, which will only show that they lacked the political sense necessary for government anyway.
If your party loses an election, change the leader, behave like an Opposition and hammer away at the weak spots of the Government before it gets the chance to settle down. Then, think about how you might plug those weaknesses, and then share those thoughts with voters at election time. Don't present yourself as an aggrieved party to the very people who tossed you out, or you'll just give a comfortable majority to a Government that won't necessarily do much with it (see NSW since 1999, Victoria since 2002).