Once you have cut and hung your plasterboard it's time to finish internal corners.
Rest one end of a broad knife on the tape in the corner and the other end on the plasterboard for an even taper.
Cut the tape to length and fold in half lengthways. Apply the first coat of compound with a 100mm broad knife.
TIP The crease stiffens the tape and helps keep the corner straight.
Position the tape near the ceiling, lightly pulling the knife down to bed the tape in the compound. Apply two more coats 150mm either side of the joint, feathering the edges.