Open a bucket of joint compound. Use all-purpose joint compound for taping, repairs and texturing. Mix the mud with a mud-stomper tool similar to a giant potato masher or use an electric drill and a mud paddle. Add a cup of water and mix to a consistent texture with no lumps.
Scoop the joint compound out of the bucket with a 6-inch drywall-taping knife and fill up a stainless steel joint compound pan. Use a 6-inch knife to apply the mud when taping butt joints and corner joints. Apply a coat of mud under the tape and another coat over the tape. Load one corner of the knife and run one edge along the wall when smoothing corners.
Smooth the mud over the joints with a single stroke. Scoop globs of mud from the pan, keeping it centered on the knife so no mud is on the knife's corners. Scrape compound off the corners on the edge of the pan if needed. Hold your thumb on the knife handle and press your index and second finger on the knife blade on the opposite side.
Apply the joint compound generously, holding the knife vertically at the beginning of the stroke and reducing the angle as you go. Put just enough pressure on the knife to smooth the compound, but not enough to remove it all. Use the knife edge to squeeze out excess compound and air bubbles from underneath the tape.
Load up a 12-inch knife with joint compound to finish the tapered, or recessed joints on the long edge of the sheets of drywall. Apply it in a single long stroke until the knife is empty. Put the tape on, then cover it with a coat of mud. Smooth the joint with the 12-inch knife, applying enough pressure to bend the flexible blade. Go over the edges lightly to feather them out.