Cloning a fruit tree simply means making an exact copy. Exact copies can't be grown from seeds due to the fact that seeds mix genetic material from two different trees. The only way to make an exact clone of a fruit tree is by taking a cutting and grafting that cutting onto a root stock. A cloned fruit tree will produce the exact same size fruit with the exact same taste as the parent tree from which the cutting was taken, above the point at which the graft was made.
Cut the tip of a branch of a good fruit tree, one that produces excellent fruit. This is the tree you will be cloning. The tip should be new growth (this season's) and should be approximately 4 to 6 inches long and about the same diameter as the trunk of the root stock you will be grafting it to. Remove any leaves within the first 2 inches of the cut end.
Select a root stock to graft your cutting (scion) into. The root stock should be from the same tree species (graft apple to apple roots, oranges to orange tree roots, etc.). The root stock will most likely be grown from a seed. Plant your root stock where you wish your tree to grow or you can perform the graft while the root stock is growing in a container.
Make a sloping diagonal cut in the scion at the cut end. This cut will make the scion come to a somewhat sharp point. The cut should be approximately 2 inches long.
Make a similar diagonal cut in the root stock just below the first leaf or branch. Again, make the diagonal cut about 2 inches long. This will entail, in effect, cutting off the top of the root stock. The two diagonal cuts should fit together so that the scion will appear to be an extension of the root stock from the spot where you made the cut.
Fit the diagonal cut on the scion to the diagonal cut on the root stock. The cambial wood (the wood just below the bark) of the scion needs to be in direct contact with the cambial wood of the root stock. If the two pieces don't align perfectly, match the two cambial sections along one side.
Wrap grafting tape (available at any nursery) around the two pieces, starting on the root stock and winding your way up. The tape should hold the two pieces together firmly.
Cover the wrapping and a bit of the root stock and the scion with grafting compound. This is a sticky liquid that can be applied with your fingertip. Cover the area to keep it from drying out.
Keep the soil moist and allow your tree to get plenty of sun during the day. Once new leaves begin to grow from the scion, remove the grafting compound and the tape.