You can choose from several types of mantles, but two of the most popular are bracket mantles and floating mantles. Bracket mantles look like a traditional shelf above a fireplace. Floating mantles, however, give the appearance of a shelf floating above the fireplace because the shelf brackets slide inside the shelf itself.
What is placed on the mantle can determine how the mantle is hung and how high. For example, a mantle used to display pictures, knick-knacks, Christmas stockings or other small, lightweight items might use lighter materials and require less work to assemble than a mantle that will act as a base for a flat-screen television or large, framed picture. Also the height of the items displayed will determine how far above the fireplace the mantle should sit.
For both the bracket and floating mantles, you need a drill, stud finder, pencil and ruler for proper measurement and installation. Another important tool -- the level -- will help ensure the mantle is straight and balanced so its contents do not slide off.
When mounting or hanging a mantle, you will want to ensure the items placed on the mantle are at eye level, otherwise no one will actually see the content of the shelves. Most mantle shelves are no more than a few inches above the fireplace itself, so, if the mantle is going over a working fireplace, make sure both the mantle and the items placed on it are resistant to heat.