Buy a cardboard concrete form from a hardware store. You can usually find tubular forms for deck footings in various lengths and diameters. Choose one with the diameter you want.
Use a handsaw to cut the length of the concrete form to get the height you want.
Place a piece of plastic on a smooth surface and put the form on it. Using a smooth, even surface ensures that the pedestal will be level.
Mix one part cement, two parts sand and three parts gravel. You can also get ready-mix concrete instead.
Pour the cement into a container and add water little by little. Use a spade to mix the cement with water until you get a uniform, pudding-like consistency.
Have someone hold down the form firmly as you pour the cement mixture in. This prevents the cement from leaking out of the bottom.
Shake the form from side to side to remove any air pockets.
Place a heavy object on the form to keep the form still and prevent the mix from leaking. Let the mix dry for 48 hours.
Peel off the cardboard form and leave the pedestal to cure for one week.
Paint the pedestal.
Apply concrete sealer using a paintbrush to protect the concrete from water, dirt and chemicals.