Never dwell on the negative ...
There is a person in my life that is a professional "Debbie Downer". You know the type, hyper critical, always anticipating dire outcomes, untrusting of overtures of kindness. Over time this person's face has developed a sour, hawkish expression that can be very off-putting to others - especially in casual social interactions.
I think that our physical appearance reflects our inner attitudes. Frown lines, perpetual furrowed brow, laugh creases around the eyes, stooped shoulders, 'pep in the step', head thrown back and looking intently at surroundings. All of these are non-verbal communications that are received and processed before we even open our mouths.
I want people to anticipate a conversation or encounter with me, not groan inwardly or studiously avoid making eye contact. So it is my responsibility to have an appearance that is warm, welcoming, kind.
One way to do this is to look at (and for) the good, and not dwell on the negative. A good way to go forth in a pleasant mood is to make your morning a time of happy news. Leave the wars and pestilence for a brief respite of calm and humor and affirmations. That way the most recent information roiling about in your mind will be more apt to leave a hint of a smile on your lips instead of a glowering frown.