When drawing in PS, I always have a duplicate window in the other monitor at 100% or 50% zoom so that I can "step back" and see how things look in gestalt. That way I don't have to zoom in and out and re-rotate as much.
Even something like the dinky preview window would work, though I like just having it be a a simple window
I much prefer sketching in Sketchbook, but when working on a fiddly bit, like the precise angle of the eye or somesuch, I end up rotating the canvas, making a mark or two, zooming to fit, Undo-ing the mark, zooming back in, re-rotating, then repeating, until I get it just so.
Between the history window and the duplicate window, these are the two features I really miss from Photoshop.
secondary window