Hillsound stool from Outdoorsmans, Helinox chair one, Crazy Creek Hex 2.0, simple foam pad. Used them all and more in different situations and how heavy I want to carry. Other than just a simple foam pad the Crazy Creek is the most universal for me, quick, comfortable and works pretty much everywhere but not the lightest option.
Helinox Chair Zero. I am critical when it comes to packing weight, every ounce matters.. but as I get "older" these types of things become really really nice to have during long back packing hunts. for back at camp, or when glassing for hours at end.. its definitely nice getting off the ground for a bit. I also bring a therma rest-z seat for its multipurpose uses.
I have a foam pad that hangs from the two load straps on the bottom of my day pack. It’s right there when I need it for short sits without even dropping my pack.
if I’m planning on spending more time in a spot glassing I use a Helinox. Lightweight easy to set up and a nice height for the spotting scope.
Usually just use a foam pad. A chair would be nice, but in the steeps it’s not really realistic. You’re lucky to find a relatively flat spot to shoot from, much less a spot flat enough for a chair.
I like the Helinox chair zero, weight is about a pound. I've also seen others, Amazing Wilderness Products has one at about 3oz and $20 that can be hung from long sticks tied together into a tripod.
Or buy it...I bought one a short while back and am pretty sure I paid less than $20 for it. Haven't used it on a hunt yet, buy preliminary testing in the yard leads me to believe it is just what I was looking for; extremely light weight with good back support for those trips where every ounce counts.