Grab your phone.
Set your timer for one minute.
Close your eyes. Feel the breath moving in and out of your nostrils. Focus there, on the feeling of the breath flowing in and out of your nose, And do nothing.
While you’re trying to get your brain to do nothing, notice what it actually is doing.
If your thoughts starts making plans, notice it. Think ‘planning’. Then stop the thought and return the focus to your nostrils.
If you start worrying, think ‘worrying’, then stop the thought and go back to your nose.
Continue focusing on your nostrils. Labeling any thoughts, planning, worrying, fantasizing, remembering, listing, counting… And return to your nose.
When the timer goes off, stop.
Notice how you feel.
Perhaps you can try this a few times throughout the day noticing which kinds of thoughts keep occurring.