White tea is a delicately-flavored tea that is made from the silvery-white unopened buds and immature leaves of the tea plant. Some varieties of white tea are made only from buds, without any leaves. Steam the leaves on the stove top for about 1 minute and then dry them in an oven for about 20 minutes at 250 F (121 C) immediately after harvesting. Brew immediately or store the dried leaves in an airtight container for later use. Green tea is made from leaves that have been minimally processed. After harvesting, allow the leaves to wilt in the shade for a few hours, then steam them on the stovetop for about 1 minute. Dry the leaves in the oven for about 20 minutes at 250 F (121 C), then brew. You can also store the dried leaves in an airtight container and use them later. After harvesting the leaves, allow them to sit in the sun for about 1 hour. Bring the wilted leaves inside or place them in a dry, shady spot for 10-24 hours. Gently mix or stir the drying leaves occasionally to aerate and gently bruise them. If you wish, you can either dry the leaves briefly in the oven (20 minutes at 250 F/121 C), or skip oven-drying and roll the leaves into small balls before brewing. After harvesting the leaves, "massage" them by rolling them between your fingers and hands. Do this until the leaves become darker in color. Spread out the bruised leaves on a flat surface and put them in a cool, dry place. Allow them to air-dry for 2-3 days. Complete the drying process by putting the leaves in the oven for 20 minutes at 250 F (121 C). Store the dried leaves in an airtight container.

Summary:
Gently dry unopened buds to make white tea. Brew freshly dried leaves to make green tea. Wilt leaves in the sun and dry them in the shade to make oolong. Massage and air-dry leaves to make black tea.