I talked about this in my farewell talk a bit, but Elder Bednar says it perfectly:
"The object of our prayers should not be to present a wish list or a series of requests but to secure for ourselves and for others blessings that God is eager to bestow, according to His will and timing. Every sincere prayer is heard and answered by our Heavenly Father, but the answers we receive may not be what we expect or come to us when we want or in the way we anticipate. This truth is evident in the three examples I have presented today. "Prayer is a privilege and the soul’s sincere desire. We can move beyond routine and 'checklist' prayers and engage in meaningful prayer as we appropriately ask in faith and act, as we patiently persevere through the trial of our faith, and as we humbly acknowledge and accept 'not my will, but Thine, be done.'"