The one thing I can not go without is my binos. To keep it light and fast I would recommend a range finding bino. I have tried many in my 19 years of guiding. The two I recommend are the swarovski EL range TA and the Leica Geovid 3200.com 10x42. Both have a short range distance, the glass is impeccable, they are durable and fast. I have gone to the swarovski el range due to size, weight and glass clarity. Using a top knotch spotter to find or decide whether the animal you are looking for is the one you see can save a lot of miles on your boots. If it's possible to pack one I always do. The lightest and best glass I have found is the swarovski ATX 65mm.
Packs can make or break a hunt due to comfort and features. I believe Mystery Ranch makes the finest packs on the market for hunting. I have packed elk out with everything from the smallest pop up 18 to the Beartooth, all with no failures. For extended hunts or long pack-ins with changing whether I would go with the Metcalf or bear tooth. Both will keep your gear organized and accessible. Dry and blood free when packing meat out. For day hunts I like the pop up 28 or pop up 38. Light small and out of the way....until you need it. Then the frame feels just as sturdy and capable of packing out full loads comfortably. I like light and small to maximize the items I can have to be prepared for anything. These are a few necessary items I won't go without.
As easy as it is to sleep after a long day in the back country, it's still very important to have light weight comfortable gear that will allow you to stay as long as it takes. Tents should be light and pack small. An insulated sleeping pad can make all the difference in keeping you off the cold ground and the sleeping bag you choose typically fits the old adage "you get what you pay for". The Big Agnes system keeps the pad attached to the sleeping pad so you stay on it and stay warm while keeping your pack light and small.
Go light and stayed fueled= Stay longer.
I have tried and tested different brands in some of the roughest places. There are many good brands out there and all have pc the make the full system it takes. Choose things that dry fast, breath well and are tough as nails. I bring 2 of each baselayer allowing to completely dry each pc every other day. Merino wool or synthetic will last without smell for much longer if you dry and change out each day.
When it comes to bows and equipment again I go to light and small, with heavy arrows for elk to ensure pass-through when the shot isn't perfect. Choose what fits you the best and what you shoot the best.