To make a river stone mat first you have to gather or purchase river stones. After that take a plastic mat and arrange all the stones on it. Then stick all the stones one by one to the plastic mat by using silicone sealer. Let the sealer dry completely.
Reuse an old tree to make a log pathway in your garden. Good use of "yard" trees and other wood that can't be milled; works much better in climates without termites. Good drainage under the log rounds will make the path last longer.