Decide where you would like the rain chain to be. Typically, the chains are located near the entrance to the home, close to the garage or from the corner of the home. Visibility is important in the placement of the chains. Use a tape measure and measure from the ground to the downspout opening of the chosen area determine the length of chain to purchase.
You have an option of choosing different kinds of links or chain. You can purchase a length of chain from the hardware store, use shower curtain hooks or large sized metal key rings. Additionally, you will need a v-shaped gutter hanger, metal stake for staking into the ground or any type of half barrel to catch the rainwater for use in the garden.
Remove the existing downspout from the gutter if your gutter has a downspout that is straight down. For gutters that have side downspouts drill a 2-inch hole near the end of the gutter for placement of the rain chain and place a cap on the end of the gutter. Interlock the links together creating a chain. If your water runoff is heavy, you may want to consider strengthening the chain by using two links together. This will make a more visually appealing look as well.
Slip one end of the chain onto the gutter strap and push the ends of the gutter strap into the hole you created or the existing downspout hole. Let the chain hang to the ground. Slip the ground stake over the last chain link and pound into the ground. You are finished with a basic rain chain.
Make a decorative rain chain by using any number of items at equal distances throughout the chain. For example, use small terra cotta pots along the length of the chain. Drill 3-4 small holes around the lip of the pot and connect it to the main chain by slipping the chain through the hole in the bottom of the pot. Use small key rings, interlock them from each hole in the sides of the pot, and attached to the main chain to anchor it.
Alternatively, use whole or half rain barrels for the rain chain to drop into if you prefer catching the rainwater to use in the garden. Instead of the stake, tie a rock to the bottom of the chain to hold the chain in place in the bottom of the barrel.