Try as we might - tossing, turning, fluffing the pillow, pounding the pillow - sometimes we just can't fall asleep. After offering some good suggestions on how to get a better night's sleep, a news article concluded that there really is no "right way" to sleep. There are numerous reasons why sleep eludes us, many of which we can't do much about. But sometimes unwanted wakefulness is caused by anxious thoughts, worry or guilt.
It's then that the example of David in Psalm 4 can help. He called out to God, asking for mercy and for God to hear his prayer (v. 1). He also reminded himself that the Lord does hear him when he calls on Him (v. 3). David encourages us: Meditate within your heart on your bed, and be still (v. 4). Focusing our minds on the goodness, mercy and love of God for His word, our loved ones, and ourselves can aid us in trusting the Lord (v. 5).
The Lord desires to help us set aside our worries about finding solutions to our problems and place our trust in Him to work things out. He can "put gladness" in our hearts (v. 7). So that, we might "lie down in peace, and sleep; for You alone, O Lord, make us dwell in safety" (v. 8). Even we cannot sleep, God can give us rest.