Here is an interesting TED talk about the importance of sleep.
“Walker shares the wonderfully good things that happen when you get sleep -- and the alarmingly bad things that happen when you don't, for both your brain and body.”
Note - you can’t ‘catch up’ on sleep, there is no sleep debt.
Tips for better sleep at about 14:30
restrict caffeine use
keep a routine (as I mention elsewhere, the most important part is to wake up at the same time every day, including weekends)
if you’re in bed for a while and can’t get to sleep, get up and go somewhere else and do something relaxing, then return to bed
keep it cool - around 18 degrees celsius