If you snooze, you lose (or die)
After a decade of night freight I can tell you this:
1. Learn to pace your day and nap consistently. Eat well. Exercise well.
2. Avoid a dependence on caffeine or chemicals. The crash afterwards is more dangerous than the fatigue. I can recall a single-pilot flight where I was blacking out in fits after attempting to stretch my day with caffeine. I was into the sun all morning. I barely got it on the ground and then blacked out for 45".
This is no joke. Never again.
3. Good food. Carry enough for each day. A crew-car run to Mickey D is not good food.
4. Learn to power-nap. This is an acquired skill. I need 30" or so, but I am good for 3-4 hours.
4. Learn the magic words: "Too fatigued to fly." Those words on a recorded line will protect you.
If you are new to the sadistic world of night freight and sleep deprivation, be careful until you know your limits. Be safe!