Determine ahead of time the desired location and dimensions of your trench ditch. Mark off the dimensions with a tape measure and spray paint.
Adjust the rototiller setting to a depth of 4 to 6 inches. Turn on the rototiller and push it forward, following the manufacturer's instructions, over the marked trench ditch area. The rototiller's tines roll over the soil and dig it up the packed dirt. Keep your hold level on the rototiller to make the depth consistent. Once you roll over the entire area switch off the rototiller. The top layer of soil in the trench area should be loosened and easier to dig up. Set the rototiller aside.
Dig up the loosened soil along the trench line with a shovel. Discard the soil into a wheelbarrow for easy removal.
Restart the rototiller and pass it over the area of the trench to loosen the next layer of soil, once the first layer of loosened soil is removed. Shovel up the loose soil and discard it into the wheelbarrow.
Continue loosening the soil layers with the rototiller and shoveling out the loosened dirt with a shovel until the trench ditch obtains the required dimensions. Check the trench ditch dimensions with a tape measure to ensure they are correct.