John Gruber draws my attention to a post on Macworld by the redoubtable Glenn Fleishman wherein he tries to solve a reader’s problem about getting Finder windows to open at a consistent size and location.
I read the trick for doing this many years ago (though where I can’t remember), and it’s always worked; it’s a little simpler than the suggestion Glenn follows. (And yes, you could argue as Gruber does that the fact that no less a man than Glenn doesn’t know this suggests it’s far too hidden and therefore broken a behaviour, but I’m here to solve this problem for you rather than bellyache.)
To have Finder windows in OS X open at a consistent size and location, open a new Finder window, resize it to how you want, then, and this is the important bit, close it again before you do anything else. Just open the window, resize and reposition it, then close it. Don’t click icons inside it. Now, subsequent new windows will be at the same size and position.
Here are a couple of bonus tips I always use. The first is that as well as resizing and repositioning the Finder window itself, you can also change the width of the Sidebar and the columns in column view – I always default to column view – and these will be remembered too. The Sidebar will actually snap to width of the widest thing listed, which can be handy. To adjust the column size, hover over one of the vertical dividers and drag; so far, so obvious. The extra little tip is that if you hold ⌥ then all columns resize at once. You can do both these adjustments on the new window you open above to set the default size and position.
Second, because I am the way I am, I like my windows to be neat and central. You can do this by, when you open your new Finder window to set the position, first dragging it up to the top left corner of the screen, allowing it to be as high up as possible and actually overlapping the left edge of the screen a little. Now click the green button at the top left of the window while holding ⌥ so that the window snaps to the top left of the screen, drag the bottom right corner right down to the bottom right of the screen, then grab one edge of the window while holding ⌥ and ⇧ to resize it down proportionally; you might need to release ⇧ at some point to get a nicely balanced window, but the joy is that it will now be right in the middle of the screen, every time.
Finally, remember that you can set which folder a new Finder window opens with in the General tab of Finder’s Preferences. I have this currently set to my main work folder, containing sub-folders for all my clients, but when I worked on a magazine I had it set to a particular folder into which I’d drag aliases for all the current stuff I was working with. Some aliases – to folders on the server, say – never changed, but some were replaced every month as I’d turn my focus to a new issue. This approach meant – and means – that whenever I hit ⌘N in Finder, I get immediately shown the most relevant current stuff, and because I’d have followed the earlier advice above, the window is in the right position, is the right size, and is perfectly centred.