Summarize this article in one sentence.
Position your head so it is center of your pillow and fluff up the sides to cushion your face when you lay down on your back. The pillow barricade may help you subconsciously stay on your back while you are sleeping.  If you can't sleep on your back for long periods of time, sleep on your back for the first couple of nights after you have gotten the extensions. This will give your lashes enough time to properly set.  If you have to sleep on your side for comfort, sleep with your face off the edge of a pillow to keep the area around your eye from rubbing up against the pillow. Use a pillow made of memory foam or one that has a styled wave-shape to keep your neck and head from turning in your sleep. When your head turns, your cheek will push up against your lashes and damage them over time.  A wide range and style of these pillows can be purchased in the bedding section of a local department store, or online with major retailers. Instead of swapping out your pillow, purchase a silk or satin pillowcase. The slippery texture will reduce any tugging that occurs to your lashes while you sleep. Carefully, lift and slip the cupped mask over your eyes before you lay down to go to sleep. The cupped style of the mask will protect your extensions from rubbing against your pillow or blankets. Avoid wearing a flat sleep mask to keep your lashes from getting crushed.  These can be purchased at your local department store in the sleepwear section, or online with major retailers. Don't drape your arm over your eyes when you go to sleep at night. Even with the mask, this will apply a tugging pressure to the extensions and will eventually cause the lashes to fall out prematurely. Rubbing your eyes extensively will cause your eyelash extensions to loosen and fall out. Make the conscious decision not to rub your eyes when you wake up. This may be hard to do at first, but after a few days, you should be able to break the habit.

Summary:
Sleep on your back to avoid crushing your lashes. Invest in a form-fitting pillow that will keep you from rolling onto your side. Purchase a cupped facemask to protect your lashes while you sleep. Avoid rubbing your eyes when you wake up to prevent damaging the lashes.