Pad against my back in a pocket made for it (means no stuff sack necessary to protect inflatable pad). Sleeping bag at bottom. Food in its bag (usually an Ursack) vertically against my back. Other stuff (most of it small) tucked in around it, with heavier items lower down and close to my back. Insulating clothing in dry bag at top of pack. Shelter either in top of pack or, more likely, in one of the outside side pockets.
When I arrive at camp, the first thing I want is the shelter. If it's raining, I want to get at the tent without opening my pack, which is why it's carried in that outside pocket. Once my shelter is up, the entire pack goes inside where I unload it. I will be using everything in the pack during the evening anyway, so unpacking everything is no big deal. (I hope I won't need the first aid kit, but I want it accessible just in case). Once I'm down to the bottom of the pack, I lay out my pad (I usually don't inflate it until later) and spread out my sleeping bag on top of it so it has plenty of time to fluff up. As I unpack, I organize the pack contents close to the door so I can grab what I need without going back inside the tent. That includes my cooking pot (which contains all my cooking items) and fuel canister, the dry bag with my insulating clothing, my toilet articles, my water containers and filter . I then leave the tent with my Ursack (I don't want to leave my food lying around when leaving the camp). I then grab my water containers and head for water. I then prepare dinner, rehang the Ursack, perhaps wander off to admire the sunset, then grab the tiny stuff sack with my hygiene items and brush my teeth. Then it's bedtime. I inflate my pad, get into my base layer and crawl in for the night.
In the morning it's the reverse process, with everything packed inside the tent, starting with sleeping pad and sleeping bag, then the food, then the smaller items with the insulating clothing bag on top. Only then does the pack leave the tent. I take the tent down, stash it in the outside pocket and I'm on my way.
If you are carrying a lot of stuff you don't use every day, your first step towards lightening up should be to eliminate those items not used. That will make the packing/unpacking/organization process a lot easier. One way to do this is put a little piece of masking tape on each and every item before your trip and remove it when you use that item. Any items that go home with the tape still attached are targets for elimination. Use some sense, of course--just because it doesn't rain on one trip doesn't mean you leave the rain gear behind next time! You can save a lot of weight and bulk this way. All of us start out taking too many changes of clothing and too many "just in case" items we have less than a 1% chance of ever using.
During the "lightening up" process, the pack should be the last thing replaced. Get the rest of your gear lightened up first. While you can carry lightweight, more compact gear in a big bomber pack, it's downright uncomfortable if not painful to carry heavy gear in a lightweight pack, which is what will happen if you replace the pack first. (Just resist the temptation to fill up all those pockets!) Ideally, you should have all your other lighter gear ready to go and all unnecessary items eliminated before you replace the pack.
Have you read the articles on
the home page of this site, left-hand column? They helped me to get my total pack weight for a 9-day trip from 50 lbs. (which I could no longer carry) down to 25 lbs.
BTW, my current pack is about 40 liters and I've never had it completely full. That's another reason for waiting to replace the pack until you have comleted the rest of the lightening-up process: You may find you can get by with an even smaller pack!