E.B. Pusey (1800-1882) wrote this "recipe" for contentment. I find it quite helpful!
1. Allow thyself to complain of nothing, not even the weather.
2. Never picture thyself to thyself under any circumstances in which thou are not.
3. Never compare thine own lot with that of another.
4. Never allow thyself to dwell on the wish that this or that had been, or were, otherwise than it was, or it. God Almighty loves thee better and more wisely than thou doest thyself.
5. Never dwell on the morrow. Remember that it is God's not thine. The heaviest part of sorrow often is to look forward to it. "The Lord will provide."
From Elisabeth Elliot's book "Secure in the Everlasting Arms"