OK. I am late to this game but I'll add one more thing.
Generally speaking I will just use a spritzer bottle to moisten my baking bread. It makes the crust more cheweyer (is that a word?).
I think if you're going to put water in a shallow pan, it's better to boil the water on the stove top first. Otherwise the pan of water will rob heat from the oven.
The way I really like, because it's kind of dramatic, is to take a ladle full of water and to simply splash it against the side of the oven and then slam the door shut. Instant steam. You have to close the door quickly or all that steam will end up in your face.
You have to be careful though. If you splash any water on the light bulb covers or the glass in the oven door, they will shatter. So don't go to wild with the splashing.
After destroying my oven lights and door window, I've mostly settled for the spritzer bottle.