On a spiritual note, it's about being present
right now instead of wallowing in the past or hoping about the future. One way is to halt all thoughts and just be aware of your surroundings and your body. Like active meditation.
On another note, it's about just doing what I can do today. There's only so much weight I can lose, for instance. So I focus on just what can be done today. Tomorrow I'll think about tomorrow. This really helps me for long-term goals. Keeps me sane