+1 on the riding. Also, load the bike with more weight than your going to be carrying and ride with it. It will show what you need to work on. I have problems with climbing while touring, so right now thats what I am working on. I am working on getting ready for weeklong tour also.
Another recommendation, is remember that if it can go wrong, it probably will. It can be very trying at times, but just keep a calm head and work through it. Most important is to have fun.