If you have a lot on your mind, write down whatever is buzzing in your brain and read it after you have finished your focused activity. For me I write stuff do

If you have a lot on your mind, write down whatever is buzzing in your brain and read it after you have finished your focused activity. For me I write stuff down just before the activity and review it just after you have finished the activity. Maintaining a todo list all the time doesn’t work for me because I forget add, remove and review items on the list. Also works is sleep is your goal.