Cut and measure your soap. (For this recipe I used about 4 oz.)
Melt it in the microwave until it is completely liquid. Add your holiday fragrance oil and stir well. After the fragrance has been added, it's time to dip the leaves, but it's important that the soap be very liquid. If you need to pop it back into the microwave for 15-30 seconds to get it nice and liquid, do so. Using tongs, dip the leaf into the soap and let it sit for 10 seconds or so. After dipping, let the excess soap drip off of the leaf.
Place the leaf onto a sheet of clean wax paper to cool. When completely cooled, gently peel the leaves off of the wax paper. If there is excess soap flowing off of the edges of the leaf, you can trim this easily with a pair of scissors. (Though I've heard it described as looking like "frost" on the leaves.)
Place the leaves into a decorative bowl next to the sink. It will take some training for your guests to realize that they are single serve soaps - and that they just need to throw the leaf away when done - but once they do - they'll be washing their hands over and over again!
For complete step by step instructions with illustrations, look at Autumn Leaves Hand Soaps.