I read somewhere a long time ago, that you can make a rooting hormone from willow tree stems. I seem to remember you chop up the stem and then soak the pieces in water, to make a sort of tea. When you want to root something you just place it in the water for a while and then plant it.
All of this is pretty rusty, so I would do more research.
Gather some willow twigs and mangle them up a bit - even pound them a bit with a hammer. Put them in a jar with water and infuse them for three or four days. Use that water to water your cuttings. My neighbor, who is a heavy cutting contributor to the rhody society, has used this method for years, and his success rate is great with it.
The only drawback of the willow method is that IME it works by far best in the early springtime; if you want to make cuttings some other time of year (like houseplant cuttings right now) it has not worked as well for me as Rootone or other commercial powders.
I have a can around her somewhere, but the last time I needed it I couldn't find the darn stuff!
The next time I went to the local green house I begged a spoonful from the proprieter. You only need a a little bit. If I could find that can I'd send you a spoonful.
This blogpost seems to indicate that you can freeze willow water. Might be worth trying. I used some last spring and it seemed to work for me. I had some leftover, but didn't think to freeze it.