I shoot from so many different positions in the field from standing and leaning against a tree or off of sticks or a tripod on the front and bipod under the back end in a sitting or kneeling position.
If you're going to carry a pack with you then you will no doubt be shooting off of the pack itself frequently.
If you'e lucky enough to find yourself shooting from a prone position off of a bipod the triad tactical bags are awfully handy and easy to carry in your pack or hanging off of it for quick detachability.
Just try to be prepared for whatever the conditions require at least minimally. You can't carry it all with you so spend a lot of time figuring out what will work and carry the least shooting gear you can get away with to free up room and pounds for other more critical items like dry clothes, rain gear, food, water.
Till you make a few trips to a given area you'll just have to wing it but once you have a packing list worked out don't lose it.