Yes please Mr wavie (3 bottles of red then off to bed) Davie.
See you can make sense when you are not drinking
If you can remember that I wasn't making sense, you probably got your wife subby'd to do most of the drinking for you as well as most of your round
This is easier to show, rather than write out, but . . .
Hold the squeegee in your right-hand so that the channel is horizontal. Now rotate your arm between a quarter and half way (that's 3/8ths for any other pre-decimal dinosaurs like me) round to the left. Your fore-arm should be horizontal and the squeegee is now like a mirror image Y.
Start blading up-the-way on the left side of the pane about a foot or so below the corner and as you're moving up, bring the left corner of the channel so that it's vertical just as the right's getting to the corner, and then blade across the top edge with your channel vertical.
Repeat that corner motion as you're getting to the right corner so you come down the right side with the channel horizontal, but then turning the channel so that the right end is getting close to vertical.
Bring the blade back up in a J shaped movement and turn it left so that you're backtracking along where you've just cleaned with an overlap of an inch or two. Do a mirror image J on the left . . . back along . . . J on the right . . .
Some folk reverse the start so that they're going along the top edge and into the left corner, that's a sideways Y, then they J back.
I'm sure there's different names for the same manoeuvre. If you already use this method, what's it called in your neck of the woods? Apart from the top corner stuff, the edge bits are called Arching by some - if you're dog-earing it saves a fair bit of detailing too.
The letters A and J were brought to you by special arrangement with Dalzell Window Cleaning, and that'll be a Fiver, thanks.