Mark and saw down a piece of scrap lumber to a length that matches the width of the walkway. This piece of lumber is now your walkway spacer.
Establish the perimeter of the walkway by driving a line of stakes down both sides of the path, using the spacer to maintain the distance between the two lines.
Excavate the walkway to a depth of 10 inches. Inspect the bed of the resulting trench with a level. The walkway can tolerate a gentle slope, but any area that is seriously uneven should be smoothed over by shifting dirt with a shovel.
Pour gravel into the trench and spread it out into a layer six inches deep. Compact it with a dirt tamper.
Pour mason's sand into the trench and smooth it out with the iron rake into a layer four inches deep. Wet the sand with a hose to compact it.
Set paving stones on the sand, making sure the gaps between them are no wider than half an inch. Tap the top of the stones with a rubber mallet to settle them into the sand. If your stones are irregularly shaped, some larger gaps will result, but do not worry about these for now. Instead, finish laying stones as best you can.
Draw a cutting line around a stone in the place you need to cut to create a custom-made stone to fill one of the gaps leftover from step 6. Lay the stone on the ground and chisel out a groove along that line utilizing a stone chisel and gentle taps from a hammer. Strike the groove with hard blows and fracture the stone along the groove.
Set the custom stones into the gaps, using the same method outlined in step 6.
Pour more sand on the walkway, and sweep it into the gaps with a push broom. Soak the sand with a hose to compact it. Repeat the process of pouring, sweeping and soaking the sand until the gaps are filled with compacted mason's sand.