This one might be a little kooky. I don't even know if it works. But if it does, you might be able to make your sleep seem longer, no matter how long it actually is.
Everybody wants something different from sleep. I view it mostly as a chance to escape. It's a buffer between my days and nights, an opportunity to go far away from the working world before I have to come back. I've never cared much about waking up too rested, although it's certainly nice.
Thus, my biggest wish each night, whether I have five or six or seven hours until my alarm, is that my sleep feel like it lasts a long time. I want to avoid that horrible feeling where my cell phone beeps and I know that It Wasn't Enough. Because whether or not you enjoy your day, it's a long time until you get another chance to catch up on sleep.
But how to control sleep? It's the most mysterious chunk of our day. Eight hours can disappear in the blink of an eye, or three hours can seemingly take forever. Sleep is a maverick. It does what it wants.
Sometimes, though, it helps to ask for better sleep. Ask who? Ask yourself, or rather, your subconscious.
Say, "I'd like my sleep to last a looooooooooooong time tonight." Visualize it. When I get to the "loooooong", I picture myself traveling down a looooooong, endless road. Travel on and on for about fifteen seconds, or maybe even a little longer. Do it right before you go to sleep. Just ask politely. Don't demand.
Or make a deal with your subconscious. If you have a big presentation in the morning that's five hours away, ask for really deep, long-lasting sleep tonight, but say you're willing to give up great sleep on Friday night, when it doesn't even matter that much.
It's a simple concept, maybe even a little weird, but very few people ever try it. If it didn't work for me, I'd think it was silly to act like my subconscious mind is some entity that can be bargained with.
Now I see it as a part of my mind that wants the best for me - as long as I ask for it. Likely, it was thinking, "What the hell took you so long?" And I wake up almost every morning feeling like I had just the right amount of sleep, and that it lasted a looooooong time - no matter how long it actually was.