There are really 3 conditions which can make use of different morning eating disciplines:
1) Long run with lots of time before. Eat carbs with some protein 3 hours before, about 400 calories. There may be a crash period, but 3 hours gives time for blood sugars to recover to normal levels. At this point your liver glycogen used up during sleep is recovered, you feel OK but hungry. Eat or drink something carby and calorific immediately before starting, such as a gel and water.
2) Long run with less time than that before. Don't eat anything until 15 minutes before the run. Then have something carby and calorific, maybe more than just a gel and water. Clif bar is about the right size.
3) Short hard run. Eat as in
#1 , but 1 hour before starting. By the time your blood sugar is peaking, you'll be running and the crash won't happen. You might have to experiment with the trial food to see exactly when that peak is. The exact food is important to some people or they get stomach upset from starting so soon after eating.
4) Short moderate or easy run. Don't eat. If you don't run short on energy by the end of the run, it fits this description.