Call the locality where you live and have them come out, check the slope where you want to dig, and mark where any underground wires might be.
Start digging at the top of the slope. Dig straight down to make a wall that is about 1 or 2 feet high for the back of the first tier. Hold the back wall in place using the landscaping ties.
Measure and drill holes near the ends of each tie that are wide enough for the metal rod to fit through. Stack the ties and then stick the rod through the holes and into the ground to hold the ties in place. Make sure the rod is long enough so that it inserts into the soil about 1 foot.
Level out the ground at the foot of the wall. Make this space about 3 feet wide for your planting area.
Stack up two or three more landscaping ties at the sides and the front portion of the tier. Use lengths of metal rods to hold these in place as well.
Fill the area with composted soil.
Dig as many tiers as you need to completely cover the sloped area of the yard.
Plant your chosen vegetables in each section of the tier. Plant taller vegetables, such as corn, tomatoes and peppers, where they will not block the sun from the rest of the vegetable plants.