Two things get referred straight out. Snoring with witnessed pauses, waking unrefreshed every day, or daytime sleepiness that affects driving: that is obstructive sleep apnoea until proven otherwise, and it needs a sleep study through your GP. And restless, crawling legs in the evening that improve with movement: that is restless legs syndrome, iron is often involved, and it has its own treatment.
For everything else I want the shape of the night, because the four common shapes have four different explanations. Taking more than half an hour to fall asleep with a racing mind. Falling asleep fine and waking between two and four. Waking repeatedly and briefly, often for the bathroom. And eight hours that leave you flat. I also want to know what time the last caffeine was — measured, not estimated — what the alcohol actually is, what medications you take and when, and whether the trouble started with a specific event.
Then I check what is interrupting sleep rather than causing it: pain you have stopped reporting, reflux that only shows up lying down, hot flushes, a partner who snores. Those are treatable on their own terms and treating them is not the same as treating insomnia.
Where CBTi is the right answer, I will say so — it has better evidence than anything I do, and it is available online in Australia. What I work on is the physical side and the things above. The clinic is in Lane Cove, opposite the library, with a review point rather than an open course.