I have another good suggestion: learn pressing the left control with the side of your palm. It's usually a very minimal movement, and I find it a lot easier (and less straining) than moving the pinky to press control. The only drawback is that it doesn't really work on a laptop keyboard.
I picked that up a few years back playing World of Warcraft and some other games, to avoid having to move my left hand away from WASD as much as possible, but it has served me very well in a lot of other applications since then.
Edit: Well, that was supposed to be an answer to cheatercheater below this comment. Woops.