[header] How to sleep before an exciting event [title] Cut your caffeine intake. [step] Caffeine can stay in your bloodstream for 4-6 hours. This means that if you drink caffeine within 4-6 hours before bedtime, the caffeine will keep you awake as you're trying to fall asleep. 
Avoid drinking anything with caffeine at least 6 hours before bedtime. Some studies suggest cutting caffeine out at least twelve hours before you go to sleep.