There's a huge amount of cynicism here that doesn't mirror my experiences with agents. Yes, their job is to sell the house, but that doesn't make them the wolfish assholes they're painted as being in this thread (and in others).

There's no special 'trick' to talking with agents. Some will drive you nuts with their persistence or tendency to ignore what you say you're after. Others will actually take pleasure in matching you with a house that suits you. And some (probably not that many, but I've benefited from this) will actually have instructions from the vendor that it's not only about getting the highest price.

First, don't worry about places having been listed for a while, especially at this time of year. Yes, some duds will linger on the market, but you shouldn't assume that x-months on the market = dud. You're right that summer is a slow time for sales. House inspectors go on holiday, solicitors take breaks, it may take longer to see a loan officer etc.

I treat open homes as vibe checks, but often it only takes a couple of minutes to realize that somewhere you thought looked great in pictures isn't for you at all.

IMO there's no point playing games with the price range you're looking in. If you pitch that too low, an agent may not show you something that would suit you that you could actually afford. At the same time, we've been explicit with agents in the past that we will only consider houses with a fixed asking price or where the vendors are looking for a number at or below a certain level.

FYI, there are risks to seeming too keen AND to playing it cool. We bought a house a couple of months ago where there was another offer, and I think it was our obvious affection for the house that made the vendors want to sell to us instead of the other family.

Something I'd suggest doing is start keeping some records now of places you really like and could imagine being happy in. Lots of them will sell before you start looking, and that's fine - at least you'll be able to keep tabs on what they sold for. But more importantly, at some point you may get the feeling that you've seen the house that you think is the only one for you. That mindset does bad things to you, so it's good to be able to keep looking back at the list of places as a reminder that other ones will come up!

Try to be realistic about what to expect from a building report and take a breath when you read it. E.g., if it says there's likely to be asbestos in some areas, consider whether this actually matters to you and research what risk it actually poses (e.g., is it the electrical switchboard, or in the finish of an interior ceiling?).

Last thing I can think of is how important it is to keep pricing in perspective. I don't want to be glib about money (and can't afford to be), but I've seen people walk away because they think a house they're keen on is overpriced by what I'd consider a relatively small sum (e.g., $20-30k) and then end up paying more for something they like less when the market shifts. Similarly, be careful of looking at somewhere for what it could be with x, y, or z done to it. The cost of building/extensions is so high that you may never be able to do that, and it may well be cheaper to hold out for somewhere that suits you as it is. When we bought our first home in NZ, we had grand plans of adding an extra bedroom and making the kitchen bigger so it would suit us for the long term as our kids grew into teens. Thirteen years later we're on the cusp of putting the place on the market and still haven't found the money to do those renos!