i used to sleep 9.5hours but now i got it down to 7
I've started exercising every morning, and that helps.
Also, I think people have the mindset that '7 hours of sleep will make me feel tied' so they get 7 hours sleep, and surprise surprise, they're tired! I used to think like that, and was tired throughout the whole day, but now i think '7 hours is just enough sleep for me' and I don't feel tired anymore
Oh, oh. Also, don't complain about being tired. I know heaps of people that always complain of being tired/not getting enough sleep, and I feel that because they say this so much, that their body is making them feel more tired than they actually are. So turn that around and focus on how energetic you feel, that may work.
So yeah, try changing you beliefs in relation to how much sleep you need, it may help. Or maybe i'm just deluding myself into thinking i'm not tired when i really am