The trick is to hit ctrl with the part of your hand where your pinky attaches to it. Now all you do is rotate your wrist slightly, and you hit ctrl. Doesn't work very well on flat/low-profile keyboards, doable with thinkpads, not at all possible on macbooks.
This trick gave me some pretty bad pain in my left hand after a month or so. Remapping control to CAPS LOCK worked for me for years, but what really helped was when I switched to a keyboard that had six keys on each thumb cluster, which allowed me to map control and meta to the thumbs.
