Deck skirting can be an attractive feature that can be added to any low-level deck. You can use boards to construct a wall around the bottom of your deck. Another option is to use wood or vinyl lattice material. Make sure you leave gaps for ventilation to prevent mold from growing under the deck. You should install a door for access to under the deck. This area can be used for storage. You shouldn't anchor the skirt to the ground because frost heave will eventually damage the skirt. Constructing a deck skirt will require a lot of additional material depending on the height of the deck. Typically, lattice is sold in 4' x 8' sheets. There is also considerable added labor involved. 

Most contractors use some type of fascia to finish the edge of the deck and hide the underneath support joists. Many brands of decking actually offer fascia that will match the deck boards. However, if you are looking for a nice contrast in your deck design, you may want to opt for a fascia of cellular PVC. Low maintenance cellular PVC is available in board and sheets and comes in smooth or textured finishes. Cellular PVC products come in white but can be painted, if desired.

Under deck storage.

Here is a nice example of how you can install skirting, fascia and an access door under your deck.

The nailer board follows the ground.

Install a nailer board between support posts to attach the bottom side of the skirting or install 2x4 vertical framing flush on the outside of the frame.

Vertical skirting.

Use a piece of scrap material to space your skirt boards. In this case we used a 1/2" thick piece of base trim. Next, fasten each skirt board to the top and bottom of the skirt frame. Keep the bottom of the skirt at least 1" above the ground.

Straight lines.

Start each section using a level. Use the level every 4-5 boards to make sure the boards are still plumb.

Creating the door frame.

Install vertical 2x4 framing to create the access door opening.

Nailed in place.

Fasten the vertical 2x4 framing to the deck frame using screws. This technique could also be used to support all the skirt framing if you don't have any available support posts to attach to.

A functional storage door!

Build an access door using a Z brace. Make sure the angle brace starts at the bottom hinge and ends at the latch. Cut a 45 degree bevel at the end of the trim under the hinges to allow the door to swing, as shown in the first slide.