I use this technique for productivity focus (it is called Pomodoro Technique) : I work in 10 to 20 minute intervalls with breaks of multiple minutes in between. After every break I can reevaluate what I did and where my focus should remain on (or try to get back to one specific task if I lost focus and drop surrounding thoughts/information) and I take deep breathes, close my eyes and try to relax all my muscles with complete body awareness. It works great for me, I can be very productive in a small amount of time just by being aware of my focus, myself and my body feelings.