This is all great advice. I've struggled to fall asleep at night and waking up in the morning is probably my single biggest life challenge.

One thing I've noticed about caffeine, it may affect you more or less than others. I found out after months that if I drink any caffeine after 4pm, I won't be able to sleep until something like 1 or 2am.

Melatonin is good, but the dosage is tricky.  Personally I've had better luck with Diphenhydramine. 

Brushing and flossing plus clean sheets is really pro advice, I found this out by coincidence one day and it's wonderful.