Force yourself up at a sensible time every day, and the same time every day, as has been suggested (a good time would be to correspond with it getting light outside, eg 8am)
Sleep with your curtains open, so you are gradually and naturally awakened by the sunlight (sunlight helps the part of the brain involved in your sleep-wake cycle to reset itself - and also can cause secretion of serotonin)
Try to get out of the house every day, and get some fresh air and sunlight, especially if you are spending long stretches in rooms lit by flourescent lamps. It is also possible to get lights which mimic sunlight and have been shown to improve mood and relaxation, which may help.
Related to the above, try and do some exercise (preferably aerobic - like sports, jogging, swimming etc). Without wanting to imply anything, this should improve your fitness, which should also prevent altered sleep, as overweight people often get collapse of parts of their throat which can impede breathing and thus sleep.
Cut out caffeine and other stimulants as much as possible, especially in the evening. Tap water is supposed to be the best thing to drink later as it is less taxing for your digestive system. Similarly, don't eat large meals prior to going to sleep, and preferably have your dinner a few hours before, and don't snack heavily afterwards.
Make sure the environment in which you sleep, your odd sleep pattern could well be due to inadequate sleep. Make sure that your room is not too hot (or to a lesser extent, too cold), that you are resting your head at a suitable angle (ie don't use too many pillows), clean your sheets and replace bedding perhaps to eliminate any possible allergens which could impede your breathing.
Make sure you go to the toilet before sleep, another reason many people may have sleep disturbances is the need to urinate during sleep (and often you will not remember if you go to the toilet at night as you are in a semi-conscious state!)
Keep a notepad and pen by your bed. A lot of people have disturbed sleep patterns due to stress or anxiety, and they are kept awake by their brain running over the day's interactions or the coming week, etc. Personally I have found this to be the most useful technique, just writing the thoughts down as they come up, so your mind can relax knowing that you will remember and deal with the problems the next day. Related to this, cutting out as much stress from your life will help (i realise that this is a bit of a ridiculous statement as nobody in their right mind goes out looking for stress, and what stress they encounter is necessary for them to live their lives).
Hmm, that's all i can think of atm, will post more if i remember them
