I mist em, wile they are seedlings and in early Veg. specially if I have a low humidity, witch I often have (30-40%) once they are settled and have develop a good root net its not so much needed, I do it early in the morning (lights on) sumetimes twice a day if RH is 30% and of course away from the light/any electricity, I use as fine mist as possible, and I mist em under the leaf`s as that is where its pores is located and is where the plant "breath" as I use T5HO fluorescent light I don't have a problem sticking them in under it right away, but if I where to use a big MH light I would atlest give em 5-10 minutes to drip off a bit, I also use a water agent (not needed) to break water tension so the plant can absorb it easy (wet betty is common, I use yucca) and I only add nutrients if I see a deficiencies, otherwise it go in the soil or is there already, I also like not to use Tap water or any water with high amounts of calcium as I dont like it on my leaf`s so if I cant collect some rain water/snow I use bottle water