Heat and Humidity
As cuttings have lost most of their ability to process water a humid environment is vital to ensure they don`t dry out. Warm air holds more moisture so aim for a temperature of 80 degrees around your cuttings and try to keep humidity levels at 70% plus. A heated covered germination box or propagator is ideal but you can use clear plastic bags over pots, just use a stick or two inserted in the medium to hold the bag away from the leaves of the cutting.
Oxygen
Oxygen is important to help cuttings root. Choose a loose growing medium that lets in plenty of air and spray clones daily with shaken p.h balanced water. Ideally hydroponic clones should have their water changed daily if it`s not being moved or aerated.
Light
Place new cuttings in moderate light such as a north facing window or under fluorescent lamps. Coloured plastic bags placed over propagators make good shades from strong sunlight or HID Lamps. Once well rooted gradually increase light intensities until normal growing levels are reached. Test show that clones root best when lit for only 16 hours a day, this is due to root formation taking place during the dark period. If you want to keep your clones away from darkness however don`t worry they will still root well even under constant light.