You could use a humidity dome. They get water from the air so you need to keep it around 75-80% humidity. I've found it easiest to use peat pellets. Just soak'em, they swell up, and you put a clone in. They sell these cool trays with domes and abunch of peat pellets in them. I have had nearly perfect success with the one I use. Make sure light doesn't get to the roots. Roots are light sensitive.