Select a tree to collect your buds from that is healthy, bug-resistant and disease-free. The tree should have characteristics such as bearing a desirable fruit variety.
Choose root stock from a similar type of citrus tree to ensure that your graft is successful. For example, sweet orange varieties graft best onto sour orange root stock.
Sharpen your grafting knife before cutting a piece of bud stock from the scion tree. This will help you to avoid damaging the scion.
Mix a solution of one part bleach and nine parts water. Treat your grafting knife with this solution after cutting each bud to sterilize the grafting knife and preventing the spread of diseases.
Cut the bud away from the branch by placing your grafting knife 2/3 inch below the bud. Turn the knife at a 45 degree angle pointed in the direction of the bud and slice up and inward until the blade reaches a point ½ inch above the bud. Turn the tip of the blade so that it faces outward at a perpendicular angle to the branch and slice outward. The bud should come away from the branch along with a shield-shaped sliver of wood.
Carry a plastic sandwich bag with a tablespoon of water with you. When you have cut each bud, place the bud into the bag to prevent the bud from drying. If your scion dries out, the graft will not be successful.
Select a young sapling for the root stock that has recently produced new, vigorous growth. The plant should also be free of diseases and resistant to insects. Remove shoots from the lowest 6 inches of the trunk with branch loppers. This will give you space to graft your new bud onto the trunk of the tree.
Select a smooth, branch-free location to graft your bud onto the tree within 2 to 3 inches from the soil line. Sharpen a T grafting knife and sharpen it to avoid injuring the root stock. Make a T-shaped incision into the stem of the root stock using the T grafting knife. The incision should be 1½ inches long and should slice through the bark layer, known as the cambium, but should not damage the trunk of the tree itself.
Gently peel the two flaps of the T shaped cut in the bark back. Be careful not to damage the bark. Slide the shield-shaped sliver of bud into the pocket formed by the two flaps point side down. Fold the flaps back over the bud. Wrap the T-shaped cut and bud with polyethylene grafting tape to hold the bud in place. Do not wrap the tape over the top of the bud--leave it room to grow outward.
Check the bud in 10 days. If the bud looks shriveled, the graft has not taken. If the bud looks fresh, the graft was a success. Remove the tape and allow the bud to sprout and form a new branch.
Remove the old branch above the point where the bud sprouted once the bud forms a branch. Then remove all side shoots and stake the tree so that the bud branch is upright. This will train the bud branch into the citrus tree's dominant leader.