It's also normal for clones to wilt in the first couple of hours, but they usually stand right up again. I've found that the more light you give them, the quicker they take root. I found 3 ft away from a 400w mh to be a good distance. Light=Energy...
You'll also want to keep the medium (soil) fairly moist. It's also good to give them 10 minutes airing once a day. I usually do this before I mist, and it's a good chance to look at them all, check the weight etc. Plus, it helps you show that you care.
Give the clones a lot of space and they will transpire quicker, it's a good idea to get as many clones in as you can without them touching each other. Also a good idea to snip off heavy leaves. If they're low down remove them completely, if higher up just snip them off a little at the fingers. If it looks too heavy snip it. This will also help the plant take root quicker, as a clone doesn't need much leaf to take in available light, and it has less body to support while it concentrates on the rooting process.
Also, upward growth is not always a sign of the clone having taken root, and this may be difficult to determin in soil. I'd give them at least 14 days before considering veg'.