First, prepare your area by digging up about 4 inches of soil in the area you wish to place your flagstones. Rake the area smooth and remove any debris underneath. You may want to line your pathway with edging to give you a clear idea what the path will look like.
The gaps between the stones can be filled with many materials including sand, gravel, pebbles or mulch. We used mulch to fill the gaps in our walkway. Use a broom to sweep excess mulch or other filler material off of stones.