While some plants will root very easily indeed, I do use Rhizopon green (0.25%) for most purposes. I have tried various other powders and gels and always return to Rhizopon for its total reliability. I also use Rhizopon beige (0.4%) for trickier plants such as daphne. There is a really strong grey (0.8%) and the very weak rose (0,1%).

I have always found Rhizopon green to be an absolute benefit and use it for all my cuttings...even the incredibly easy salvias and penstemons. I often see people claiming success with lavenders but I have never managed to root a single cutting without hormone powder. Same with a number of plants which will rot off if kept under cover (convolvulous cneorum, for example.) Many evergreen plants can take so long to root that the plants are in constant danger of dessication.

If I had access to a misting station, I would probably have much less need to go with the hormones...but I struggle to maintain consistent and exact moisture levels...and because the little slips are still so vulnerable to fungal opportunists, I like to level the playing field as much as possible.