Taping and bedding drywall requires very little time but it is necessary in order to have a smooth connection from one piece of drywall to another. If you painted a wall without tape and bedding you would be able to see the line where the drywall meets. This technique is also used in corners to achieve a smooth appearance.
Apply premix joint compound over the area where the edges of the drywall meet each other. Roll the adhesive tape across the area. Make sure it is in the center of the area that you want covered.
Spread the compound across the tape. Use a 6-inch drywall knife to do this. Use the knife to also flatten as much of the mixture as possible around the edges of the tape.
Smooth out the premix joint compound. Place the blade of the 10-inch knife down on one end and drag it across to the other end. Pressing down onto the taped area will push out excess mixture from behind the tape. Remove this excess.
Add another layer of premix joint compound. Use the 10-inch knife to spread it and run the blade across to make sure to flatten out the mix as much as possible.
Sand the area. After the drywall dries, sand the area with sandpaper to make it even with the rest of the drywall.