Kevin Daum gives a great summary of several tips to help you end your day productively, which increases your chances of a good night's sleep.
A short organizing session can be relaxing and productive. I like to clean up the kitchen before bed, so I know I'll see clean counters and an empty sink in the morning. It makes me feel calm. You could also empty a junk drawer, fold clothes, just something that will be quick, and have a visual impact on your surroundings.
Clear the communications deck! I love Daum's tip about responding to all emails, even if you're only saying you saw the email and you're working on it.
Do a brain dump. If things are bothering you, or you're worried you'll forget something, get it all down on paper.
Do a quick calendar review so you can anticipate your day. Also, getting clothes ready for the morning sounds silly, but it's huge for me! Too many mornings of not having the right top clean, or not being able to find the shoes I swore I put away leave me frazzled.
Shut it down--turn off electronics, get off the phone and retreat a bit. The blue light from electronic screens messes with your sleep cycle, so even ereaders can affect your sleep and the next day's productivity.
Finally, take time to center. Meditation, prayer, or just focused breathing is beneficial to clearing your mind and improve your chances of a solid night's sleep.
Give these a try and see if they help you become more productive!