Last AUG, I did the IBA SaddleSore 1000 (1000 miles in 24 hours or less) with 2 other guys. We filled up regardless of the low-fuel light coming on or not (chance to stretch, restroom, hydrate, gear check). Had a 2-hour lunch at the halfway point and then headed home.
SOME TIPS from that trip:
1. Only use gear that is already broken in (boots, gloves, helmet, etc.).
2. Highly recommend ANY cruise-control device (I used a $10 cramp buster bit)
3. Wipes to clean helmet shield
4. Tire plug kit
5. Wet weather gear
6. Charger for your phone
7. Route mapped in advance (with gas stations marked so that you can top off every 170 miles....sooner than later)
8. Get at least a tank bag. Full set is ideal but I managed with just a tank bag and a back pack
9. Your personal and emergency contact info visibly posted on your bike/person. (I wore my dog tags and taped my wife's info under the clear plastic of the tank bag) I also phoned on at every gas stop so she knew I was OK plus she had a copy of our trip route.
10. Call your credit card company in advance and inform them that you will be on aroad trip. My AMEX was flagged for possible fraud due to the numerous gas stops. Good thing I also had my VISA.
11. Something you can defend yourself with (if crossing state lines, know the laws)
12. Be safe and have fun.