I always have a justification for never getting around to washing the windows: it cuts down on the number of bird strikes. Sadly, once in awhile they do happen.
Yesterday I found this guy splayed out beneath a window looking rather drunk. Sitting very quietly in my hand in a warm sunny spot, first with a hand over his eyes, than just wrapped up, and then perched on a finger, for about ten minutes did the trick. (I didn’t want to leave him in the snow since a) it was cold and damp, and b) the neighborhood cat had just been down at the barn.) He finally perked up and flew off to the peach tree looking vaguely puzzled but no worse for it. The trick to picking any bird up is to get over the wings and in front of the feet with most of your fingers. The feet are the tricky bit, ideally you want to end up with them correctly positioned in your hand so that they can cling comfortably. But first is to get the wings controlled. Using your other hand to shade the eyes is also a good thing.
One of our prettiest sparrows: