Place leaves between two layers of wax paper. Cover with an old towel or cloth rag. Press the fabric with a warm iron, sealing the wax paper together with the leaf in between. Cut your leaves out, leaving a narrow margin of wax paper around the leaf edge. Of course that's the old-fashioned way of doing things. You also can preserve leaves in your microwave oven. Choose fresh leaves with the brightest colors. You don't want fallen leaves that already have started to dry.
Take separate leaves or small twigs and place them in the oven on top of two pieces of paper towel. Cover them with one sheet of paper towel. Run the oven for 30 to 180 seconds. The drier the leaves, the less time they will need. Be careful; you could start a fire in your microwave if they cook too long. Be attentive. Leaves that curl after removal have not been dried enough. Leaves that scorch, were left in too long. Let the leaves dry for a day or two, then finish the leaves with a sealant, such as an acrylic craft spray. You may get even better results if you use the microwave and silica gel for drying. Place a 1G-inch layer of floral silica gel in the bottom of a cardboard box. Place the leaves lying flat.
Leaves should not touch and should be at least 1G inches away from the sides of the box. Cover the leaves with a 1G-inch layer of gel. Place the uncovered box in the microwave. You want the microwave to operate at about 200-300 watts, so if your microwave has 2-10 settings operate it at level 4. If the oven only has three to four settings, it should be set at half. If your oven has a high to defrost options, set the microwave on defrost. Estimated drying time is 2H minutes if you're using a half pound of gel or about 5 minutes for two pounds of gel.
Yet another way to preserve the leaves is to submerge them in a solution of glycerin and water. Use a mixture of one part glycerin to two parts water. Place the mixture in a flat pan, and totally submerge the leaves in a single layer in the liquid. You'll have to weight them down to keep them submerged. In two to six days, they should have absorbed the liquid and be soft and pliable. Remove them from the pan and wipe off all the liquid with a soft cloth. Done correctly, the leaves will remain soft and pliable indefinitely.
I collected the leaves shown in 2004 walking with my dad in the furry glen, Phoenix park, Dublin.