You will need the same basic tools that you would use to crystallize flowers - listed below
Clip each mint leaf off of the stalk, but if possible, leave a very short stem.
With a fork, beat the egg white in a saucer, adding a few drops of water if necessary.
Using a small paint brush, coat every surface of the leaf with the egg white. Make a thin of a layer as possible. You can hold your leaf with tweezers if needed. As you coat each leaf, lay it on the sugar, then sprinkle more sugar over until all surfaces are coated with the extra-fine sugar. Next place the leaf on the cake rack. Continue until all of your mint leaves are coated.
Set the rack full of leaves in a warm, dry place. Again a gas stove with a pilot light works well. When the leaves are starting to dry, move them to an uncovered cake rack and continue drying. With the leaves, to test for dryness, break a leaf open to check for crispness.
Store the leaves in layers separated by waxed paper in a cardboard box, they will keep indefinitely if stored properly.
you will need freshly picked violets, leaving the stems
1 egg white, at room temperature
a few drops of water
extra-fine granulated sugar, either purchased or made in a blender or food processor (just blend regular sugar until extra-fine)
Unless your flowers are dusty, do not wash. If you need to wash them, make sure they are completely dry before crystalizing. Other items you will need include two plates, one which you will use to paint the flowers on and the other for the sugar, a small bowl for the egg white, a small paint brush, a thin skewer, and a cake rack covered with waxed paper.
Beat the egg white in the small bowl until foamy, if necessary add a few drops of water to make the white easy to spread.
Hold the violet by the stem and dip it into the egg white, now lay the flower on your painting plate and carefully spread the white on every surface of the flower using the paint brush. You will have to use the skewer to open up the petals. Next transfer the flower to the sugar plate, again using the skewer to open the petals, carefully sprinkle every surface with the extra-fine sugar. Be sure not to miss any spots. Arrange the flower on the cake rack, using the skewer to place the petals back in the original positions. If you happen to knock some of the sugar off, just sprinkle with a little more sugar. Clip the stem off of the flower using scissors.
After all of your flowers are coated, set your rack in a warm, dry place, such as a gas stove heated by the pilot light. After they are partially dry, transfer the flowers to an uncovered cake rack and continue drying. This could take several days. To test for dryness, check the green base of the bloom and the heart of the flower to make sure they have no moisture. These will keep indefinitely if stored in layers, separated by tissue paper in a cardboard box.
Elf's method for mint leaves and violets works well for all kinds of flowers (rose petals are beautiful done this way, too). Just remember to get pesticide-free flowers if you're not growing them at home for this purpose. Most florists can fill your request but may have to order them in advance for you. It's very important that you have edible flowers and that their pesticide free.