Uncle Buck said it perfect.
Also you didn't mention putting your clones in water quickly after cutting, before the rooting hormone. The reason for this is to not let air into the stem. It's not necessary if you can quickly dip in gel, but if you practice this, and keeping your plugs moist, you'll probably up your success rate.
I like the $10 2' fluorescent plant light from Walmart for my clone dome. I like city water for them because I feel like the chloramine will reduce bacteria in the semi stagnant environment. I wouldn't recommend standing water, but a mist every day, lightly on the leaves and inner lid.
Good Luck!