While backpack hunting is a gear intensive game, it isn't about the gear, its about the hunt. The most important thing is to enjoy it - otherwise what was the point? Now, enjoyment can take on weird forms, and if you have masochistic tendencies and own a pair of boots and a rifle, then backpack hunting is almost certainly for you.
Backpack hunting means different things to different people, and that is going to make strategies and tips less transferable. My first thought on reading this thread title was "Always have a tarp and a sleeping bag with you.", but that will just be dead weight to a lot of people based on how they are hunting. Along those lines, take what others tell you with a grain of salt. Its entirely possible that it works perfectly for them and doesn't apply at all to you.
I tend to think of things in terms of resources. Time, effort, food, etc. If you spend all your time climbing a mountain to see the other side of it, you may lose the ability to hunt a different drainage in the other direction. If you go light and only bring 2 days worth of food up the mountain, you are not going to be able to kill something that is a day away from the top and get it back down (that one has bit me before and it sucks). There is an opportunity cost to every move you make, so it makes sense to spend a little time thinking about those before making a move.
Going uphill is a cakewalk compared to coming downhill, and especially with a heavy pack. Don't go up something you can't get back down.
Don't shoot it if you can't retrieve it.
Do what you have to do to sleep well.
Take care of your partner, switch out leading/breaking trail, keep things positive. Everyone needs a cheerleader now and then, but Debbie Downer rarely gets a phone call during hunting season.
