The other part of that verse is ". . .and know that I am God." (Psalm 46:10) Sometimes I spend so much time thinking, even obsessing at times about the things in my life or the world as if I have to solve them or figure them out right then and there. My struggle then becomes quieting those worrisome thoughts and directing my attention towards God. I have to remind myself of the need to turn those things over to Him and allowing Him the control because He IS God and I am not.
For me to be still, I have to focus my attention on God and pray without having my mind wander into the many different areas that I find myself concerned about that day. I have to pray over those things and then be willing to turn them over to Him and let go. I am still learning what it means to be still but the more I find rest in Him, the more I find comfort in my circumstances as I realize He holds every moment in His hands.