Mark the walkway area with marking spray paint.
Cut any existing sod with a shovel along the spray-painted lines. Remove sod and shovel out 2 inches of soil from the entire walkway area. If no sod exists, shovel out 4 inches of soil from the walkway area.
Set a 10-foot 2-by-4 along the length of the walkway and set a level on top. Ensure that the walkway slopes in a direction that allows runoff. Correct undesired slopes by removing or adding soil to the walkway.
Rake the walkway area smooth and spread 2 inches of decomposed granite evenly on the walkway area. Compact with a hand tamper.
Lay flagstones on the walkway area, starting at one corner and working your way out. Leave a 1/2 to 1 inch of space in between stones. Chisel stones to your desired fit.
Mix decomposed granite with an equal part of compost in a bucket. Fill the spaces in between stones with this mixture and groundcover plants. Water thoroughly according to the groundcover specifications.