I can't imagine cavemen having problems like "restless legs syndrome", and they managed to get by pretty well without CPAP machines too. The causes of these types of things can generally be found in modern diet and lifestyle factors.

The most effective things I've found in improving sleep and general wellbeing are:

- giving up caffeine;

- reducing anxiety and stress generally particularly before bed.... don't work long hours or work right up till bedtime as you can be running on adrenaline which is terrible for sleep and mental health.

- avoid diet drinks and anything containing artificial sweetener (http://www.google.com/search?q=aspartame) ... I only recently discovered how terrible this stuff is, and giving it up has done wonders for my wellbeing.

- If you snore, have sleep apnoea or any other respiratory condition, look into natural remedies like Buteyko or Pranayama... CPAP machines can help you get better sleep but are counter-productive in the long term as they reinforce your habit of hyperventilation.

- Consider seeing an osteopath or similar type of physical therapist to straighten out your skeleton and attend to any muscle tension you have - most people, particularly desk-based workers - have lots of tension which restricts blood flow, contributes to stress and reduces quality of sleep.

- Regular exercise is great but be careful if you are already prone to anxiety, as over-exercising can push you into depression (this is counter to what most people understand about exercise & depression)

- Consider detoxing and liver cleansing - I've undertaken the lemon detox ("master cleanse") about every 6 months for the last year or two, and found it's done wonders for muscle tension, quality of sleep, digestion and mental health.

Some of these points - in particular the last one - are very contentious and frequently under attack from skeptics, usually who are practitioners of conventional medicine, vendors of costly commercial solutions like CPAP machines, or professional skeptics like Skepdic, which whilst often valuable, is often skeptical about things purely because they are unconventional.

Whilst I don't have any problems with conventional medicine, it generally focuses treating symptoms of clear-cut diagnosable illnesses, and is not particularly good at addressing the vague lifestyle-related conditions like fatigue, poor sleep, anxiety, muscle tension, digestion etc.

These types of conditions can generally be overcome by understanding the fundamentals of the way the body works, and doing everything you can to help your body to work as it was designed.

It's not easy, the world of "natural medicine" is a dangerous place but my experience is that with persistence, a willingness to experiment, and a healthy level of skepticism, it has much to offer to improve your life greatly.

Some helpful links:

http://www.kuro5hin.org/story/2005/5/9/83936/58483
http://www.kuro5hin.org/story/2005/5/16/81428/8007
(I know you didn't mention any issues with depression, but quality of sleep is closely related to anxiety and depression, and can be a warning sign, and many of the same principles apply in overcoming the problem.)

http://www.buteyko.com/ - if you have breathing/snoring problems.