Rule 2: protect your fellow riders, except when in conflict with Rule 1
Rule 3: protect your equipment, except when in conflict with Rule 1 or 2
You should have 2 water bottles. You can use each to spray the nozzle of the other to clean it before drinking.
Gas stations frequently run deals on Gatorade/Powerade for 2/$3 or $2.50. It's not a replacement for water, but it is pretty cheap.
If you hand wash your clothes, rig them on the bike the next day to dry. If it's sunny.
Whenever you have a free moment in the sun, bring out your tent supplies and air them out. It pays to have them toasty dry as much as possible.
Figure out an organization system for your panniers and stick to it. That'll help for when you need to find something in an emergency, like a sudden downpour.
Plastic bags are great for organization, but they only come in so many colors and aren't that durable. Think about getting a few camping specific sacks for essentials.
Here's one way I use plastic bags -- I have a sleepwear bag. Inside are my camp/tent clothes and an empty plastic bag. I take it and my towel to the shower. I wash all my cycling clothes and put them in the empty bag. I tote both bags back to the bike. If it's not wet out, I array the wet clothes on my bike. I stuff the empty tent clothes bag in my tent for changing in the morning.
It's all about efficiency. Even if you're in great shape and have trained a lot, it always pays to take the easy way out on tour. Every little edge you can give yourself helps. When you let your form get sloppy, that's wasted energy. When you don't fully tuck in on a clear downhill, that's wasted energy. Obviously, you can't go crazy with obsessing about every single thing, but just try to identify tactics that will help you save energy.
Ride the white strip when it's safe. No cars, not wet, not on downhills. The paint is generally smoother than the surrounding pavement, which keeps you a bit more comfortable. And since it's smoother, you get a tiny bit less rolling resistance. After a few days, you'll be surprised how easily you can steer the bike between those 3 inches.
