Even when things are going well, I think we ought to make it a daily habit to look for the light, lest we forget how to find it. If that can be our constant, our touchstone, then we're never really thrown if it all goes pear-shaped, because we've never lost the ability to realize that even this is temporary, that we've been through discomfort before and come out the other side.
Because that's the charming (if painful) naivete that's part and parcel of being human--we believe that every state we're experiencing, good or bad, will last forever. We're so wrapped up (not trapped; never trapped but, shall we say, preoccupied) in ourselves that suddenly we forget physics, forget how time works, forget how all states are fluid and shifting, reflecting and refracting whatever light we choose (or don't choose) to throw on our particular situation.
So. No matter how you feel today--blissful, elated, grieving, bored, furious, or frustrated--make it a point to find and sit in the light, for a moment, an hour, or the whole darn day if you're lucky.
But anything is enough. Anything is always enough.