The Jesus Prayer. Breathe in: Lord Jeus Christ, Son of God Breathe out: Have mercy on me, a sinner. Great meditation prayer. Repeat often, and think. This is not to clear your mind, but rather to fill your mind with truth.
These prayers will put you in the right frame of mind and prepare you for your day. Choose one and pray it in the morning before you even get out of bed, or as you enjoy your breakfast and you’ll be prepared for whatever comes your way.