Gratitude

Taking time every day to do inventory of those things you are grateful for.
Some recommend doing it at night and find at least three things to be grateful for. Knowing you are to come up with a daily list, makes us more attentive to finding those things each day as the arise.
The Apostle Paul could have found plenty to complain about - but did not. From his prison cell he spoke of gratitude when he said; "I thank my God on very rememberence of you"