As soon as you are awake enough to consider about it, make a decision that will have a great day. Do not let the concern of an upcoming event take over.
If anything relating to them will focus on it for a minute and determine whether or not it is something you really have control. If so, make a decision right now to take the steps it can to make it better and minimize your concern. If there is something you can control, decide to let it go. Let it go. Save your energy for everything else we're trying to do today.
If a situation arises that is really stressed out, go through the motions of thinking I could do or what you might say, but then stop and think for a minute. Wonder if any of those things that make the situation better or worse? Sometimes doing nothing is not the best option.
Doing something for someone else is essential. Planned or spontaneous, never mind. And it has to be huge. A little courtesy from you without doubt will brighten someone's day more and feel good about it, too.
Become aware of every moment of your day. Take the time. Enjoy these moments.
At the end of your day, despite not to choose any of your options will only eat you and will not solve anything. Give yourself credit for doing the best you can today.