This phrase comes from a talk from the most recent General Conference of the Church of Jesus Christ of Latter-day Saints. If you haven't read it, you definitely should, even if you aren't LDS. The entire address has such a bright message of hope, and it makes me happy.
I've been having a few minor setbacks lately that I am, stupidly, allowing to bring me down. When I catch myself thinking sad thoughts, I try to remember to look up. Even if you take this literally, it helps. The simple act of lifting your chin is the opposite of what we (or at least I) naturally want to do when I am sad, and therefore helps me to feel happier.
What makes it even more helpful, is the spiritual implications of looking up towards Heaven. To think of the love that God has for us and of his great goodness and the plan that he has for me makes me so happy. Then to go beyond that and seek his guidance, trusting that everything will work out the way that he desires, is so comforting. Even though I sometimes am selfish and wish that his plans conformed to mine, I am always happier when I banish that thought and bend my will to his.
I am so grateful for this perspective, and for my faith so that I can trust that nothing that will disrupt his plan for me will happen. I love Him so much, and am so thankful for all that he has given to me.