Night, Night. Sleep Tight.

Silence the stimuli
About an hour before you usually go to bed, create a calm, quiet environment in which you can settle down from the stress of the day. Turn off the TV and laptop and put your phone on vibrate. Turn the lights down low.
Get cozy
Get ready for bed. Dress in comfortable loose-fitting pajamas, wash your face and brush your teeth. Even if you aren’t tucking yourself in just yet, getting dressed for bed will help set the stage for a comfortable night.
Sip something warm
Whether you fancy a cup of heated milk or some soothing chamomile tea, sipping something warm before bed can help your body relax, which can aid you in falling asleep. Warning: Since pregnant women already struggle with getting through the night without at least one trip to the bathroom, serve yourself a small cup.
Change your position
Trying to adjust to a new sleep position (such as the suggested "on your left side with a pillow between your legs"), can take some time. And it may never be the most comfortable position for you. So give yourself a break and try out a few other positions (just stay off your belly, especially in the latter months) and use pillows to help prop up your body in various areas until you are comfortable enough to relax.
Meditate
There is a lot to think about when you’re expecting so many women lie awake at night ruminating about all those “what ifs” and making their mental what-to-do-before-baby-arrives checklists. If you're one of those women, try meditating before bed to clear your mind of concerns.
Continual sleep problems
If you are experiencing night after night of tossing and turning or pain in your back or legs (or anywhere else for that matter!) that is preventing you from getting your shut-eye, check in with your doctor to ensure there is not a serious issue at hand.
More pregnancy
How to get some sleep during pregnancy
Best pregnant sleep position: The left side
5 Gadgets to maximize sleep during pregnancy