Load a small amount of plaster onto the hawk with the trowel. A hawk is an item that has a flat metal surface and a handle that plaster is placed on. This allows you to climb a ladder and keep a working amount of plaster with you.
Use the corner trowel to place a small amount of the plaster in the corner of the room. It can be difficult for the beginner to use the corner trowel to place the plaster from the hawk to the wall. If you do not feel comfortable using the corner trowel to apply the plaster to the corner to start, you can scoop a little section off of the plaster on the hawk and then set it in the corner with a flat trowel. From here, you can spread the plaster with the corner trowel.
Hold the corner trowel at either the bottom or top of the the plaster and gently push up or down, depending on where you start. Make sure the point of the trowel is in the corner. It does not need to be firm since you are going to want to have a thin layer of plaster in the corner. Continue this process until the entire corner is plastered.