When I detect a bit of worry in my thoughts, the best thing I can do is take that thought captive and give it to Jesus.
"We demolish arguments and every pretension that sets itself up against the knowledge of God,
and we take captive every thought to make it obedient to Christ."
II Corinthians 10:5
Here is a little something else I do...
I doodle a prayer!
This actually happens to be a doodle prayer for my youngest son Samuel and three of his good friends. They all play football together on the same team. Often, I find myself in "worry mode" over this high contact sport.
I actually put this prayer on my refrigerator so every morning...every time I open the fridge...or pass by it...I am reminded to pray for these little fellows. Sometimes I just repeat one phrase I wrote over and over the entire day. Somehow, God takes my worry away and I rest at peace knowing He is watching over my son and his friends.