Question for shirtmakers/tailors

[polar-lemon]

Given all the DIY tailoring threads that have been popping up, I'm interested in doing some basic shirt alterations. Particularly, I want to try to learn how to close up a box pleat and to add darts. I've found much information about darting- some say you need a sewing machine, others don't. However, I've found nothing about closing the box pleat. Is this just as simple as it sounds- determine the size of the pleat, iron it into the shirt, and then sew it together from the inside? For the darts, is it as simple as pinning and sewing from the inside?

Obviously I will do a few trial runs with some bad shirts before attempting anything serious, but any advice or tips offered would be greatly appreciated.