My favorite item is a leather rifle holster or gun cradle to rest the rifle's buttstock in when walking through the woods.
It's made of leather, and is similar to a shallow pouch that fits on a belt worn outside my jacket.
I rest the buttpad inside that pouch and the gun is supported in an upright position with just one hand.
Then I can walk though the woods or maneuver through the brush with at least one hand free at all times.
It allows me to tilt the gun into different positions, while only supporting a fraction of the gun's weight with my arm. The arm muscles won't be as fatigued when it's time to hold the rifle steady to fire it.