A couple of years ago I heard that one should press Shift/Ctrl/Alt using one hand and other key(s) of the combination using the other hand. At first, it was awkward. I had felt that I was soooo slow. But after a week or two I got used to it. Now I can't even imagine going back to using just one hand for the combos and for sure the stress on my wrists is lower.
Pressing, for example, Ctrl+C is simpler with the left hand only and if one uses sticky keys then it's two separate keypresses, no stressing of the wrists needed.
