Live for the moment you're facing.
Take care of today, and tomorrow becomes easier to deal with. Don't waste precious energy worrying about what you have to do tomorrow.
It's like the person who doesn't sleep well because he's worried about the future, and then he can't perform well today either because he's too tired.
This is self defeating.
Spend more time DOING and less time complaining. Too often, people who feel stress start complaining about how much pressure they are under.
This is all wasted energy, energy that could be used for something else.