I often use a walking staff( stick) when hunting, as it helps me move slowly, negotiating the stick through brush forces me to pick up my feet, and concentrate on making less noise, and give me a great shooting rest no matter when a shot occurs. Just stick the staff forward of you about 3 feet to it is leaning backwards towards you. Hold it with your left hand,( Right handed shooters), and stick your thumb out to reast the forestock of your gun. You can use this standing, sitting, kneeling, or any position in between.
I also sometimes us a tracking stick, made from a ski pole. I remove the basket and point, and replace them with a table bumperpad. The handle comes with a wrist strap which is very handy, and the pole is hollow, and made of fiberglass wound around a base, so it is lightweight and very strong. Mine is about 4 feet tall, which is just a little short for me to use as a standing rest, but It works great from a kneeling position. Again, I put the base of it in the ground about 3 feet in front of my forward foot, and then lean it back towards me. Unlike cross sticks, which can limit movement in event your game is moving across your field of view, the single walking staff allows you movement with your gun without changing your position all the time.