Crown moulding is one of the lowest cost additions you can make to a home that has possibly the greatest impact and highest return on investment. The addition of decorative moulding enables you to transform any ordinary living space bringing it a new life, charm and elegance. The installation of crown moulding can certainly be a do it yourself type of improvement. However, if you've decided to take on your own crown moulding installation project there are some guides you should follow to make your job run smoother and avoid material waste.First, find out what you need for materials.You will need to determine what type of moulding and how much of it you will need to buy. You will need to measure and mark your walls for the best estimate on materials. Measure each individual wall and round up to the next foot. If any of your walls measure within a few inches of a length of auto mould always buy the next size up just to be on the safe side.Second - create a plan of attack.We will be installing each piece of moulding in an ordered sequence, so we should do a quick sketch of the room, top view, as if we were looking down to see which wall we start with. Let's make this a bit easier and start with the wall opposite the door and then number each wall going counterclockwise.Let's also set up our guides for installation on the walls. Hold a piece of moulding at each inside and outside corner to mark the position of the bottom edge. Use a chalk line stretched between the two opposite ends to mark the wall for your installation line. Also, locate and mark the position of studs and joists just below the installation line.Third - install the first length.Measure your starting wall and cut the first piece of moulding square at both ends using a miter saw. Then align the piece of moulding with your installation line and begin nailing 8d finish nails working from the center out. Make sure that your nails are centered in the moulding between top and bottom.