I create slings, as needed, but for my gun carried muzzle down, on my off-shoulder, so that I can lift the muzzle UP to clear brush, or the ground when climbing slopes. I found that slinging a gun over my shoulder Muzzle Up simply guaranteed that I would catch the gun barrel on every overhead branch, limb, vine, etc.
The second advantage of carrying the gun muzzle down on your non-dominant hand is that it allows you to control the rifle with your forehand located on the Forestock of the rifle, making it much smoother to lift that gun up to your shoulder to fire, if an opportunity presents itself. I taught myself to stick my Right Elbow Out to catch the loop of the sling as I mounted the gun, so that I could put tension on the loop as soon as the butt touched my shoulder. As an alternative- with a sling that is longer, and non- adjustable-- I wrap my right wrist through the loop as I am bringing the gun to the shoulder, and that puts tension on the gun to help steady my aim. ( I am LHed. Do everything here the reverse if you are RHed.) :thumbsup: