I use a 5 gal bucket filled with NON city water. Get a willow limb 
and cut 2-inch pieces. A good double handful. Put the willow pieces 
into an old pillow case, sock, etc. and tie the top. Toss it into 
the water bucket-it is better if the sock is weighted to the bottom 
of the bucket.

Sit it out in the sun for....3 or so days. Then use this water for 
rooting cuttings, or watering new transplants. (10 parts regular non 
city water to one part willow water).

Jon

There is no exact way to make it. I mix different blends at times for 
specific jobs. The above recipe is my basic one.