Measure the outer sides of the deck. Sheets of wood lattice come cheapest in 4-by-8 feet measurements. Determine how many sheets you will need by totaling up the square footage. A 4-by-8 sheet measures 32 square feet.
Dig a 2-inch trench around your deck. This will allow the lattice a tight fit once you've installed it.
Cover the longest open stretches (without turns) of the deck first. Drop the sheets of lattice in the trench, and cut them off at the deck-line. When you've reached a good fit, put two or three nails into the sheet of lattice to secure it in place.
Repeat until the deck is complete. Use the saw to cut your sheet around any grooves or poles that might be in the way. Use the scraps you've cut from the large sheets in the smaller, tighter areas if you can.
Once completed, push dirt back into the trenches to secure the lattice in place.