Here's a side shot of my typical packing method.
It consists of a large back bag (4000+ cubic inches), a tent and sleeping pad strapped to the top bar of the pack frame, and a front bag. Maxed out those 3 locations give me the capacity to carry 6000-8000 cubic inches of stuff. I like to keep weight down but don't worry about volume.
So packing goes roughly like this:
Big Back Bag (uncoated nylon)
(1)A 10" diameter stuff sack (inside a trash compactor bag) contains sleeping bag and all other clothes I want to keep dry. This goes in the bottom of the big back bag and helps form its shape and gives me a nice platform to set the rest of the stuff on. This stuff stays there until I make camp.
(2)Food goes on top of the 10" stuff sack. The largest of the bear cannisters easily fits horizontally here. When I backpack at the ocean a 6 gallon plastic bucket with lid sits here vertically. A stove, cooking gear, water filter, etc. would also go here.
(1) Tent, poles, stakes, cooking tarp, etc. go in a stuff sack, buckles to the top bar and hangs horizontally.
(2) Foam sleeping pad is buckled to and hangs horizontally from tent bag.
Front Bag(uncoated nylon)
(1) Bear spray and monoculor clip to front bag for ready access
(2) One to two quarts of water go inside front bag
(3) Everything elso I want handy goes in front bag (e.g. hat, mittens, hanky, first aid, map, compass, writing paper, personal locator beacon, signal mirror, gun, etc.
A large back bag is a real luxury, in my opinion. Most packs would not easily accomodate a 6 gallon plastic bucket, for example. A couple trips ago my wife found a 12" diameter fish float. It easily fit into her pack on the way out. It would not fit inside a pack that had a diameter of less than 36".