Hi!
I use my middle finger for the apple control key. I usually have my fingers on the touchpad about the time I want to use the apple key. I am a strange touch typer, however.
Really, it is all based on what YOU are comfortable with. If you find it ackward, if 1,000,000 people say its right, its still wrong. Experiment.
Touch typing is one of those beautiful, adjustable skills. 🙂
Once you find one that is comfortable, just make certain that you keep doing the same thing, or you won't learn the keys perfectly. 🙂
Good luck!