The physical activity of any sort before bed is great advice. Especially if you prefer not to smoke. You can also do things like meditation or yoga before bed. There are certain exercises specifically geared for sleep.
If you prefer smoking (even if not) then I highly recommend breaking up your sleep patterns. Set your alarm for about 3 hrs in. You can adjust it more or less to your liking.When I want to dream I probably set my alarm two or three times a night to get the best results. Its even better if you can actually get up and do things in between sleep sessions.
