Meditation. First and foremost, before any other form of prep. Because I want to do it all that from 𝘵𝘩𝘢𝘵 place.
I like to review my weeks, and start to think about the next one coming, during my slow and laid back Sundays. Relaxed is when the mind is actually the most awake. This, too, is a meditation, of sorts. All daydreaming is, and we could all stand to do much more of it.
Then each day begins with a meditation. Before my phone comes off airplane mode (and, please DO sleep with it in airplane mode). My first moments are always with myself, no notifications of any kind allowed.
Again, I like to do my planning, and also my responding, from 𝘵𝘩𝘢𝘵 place. I dream the life I'm stepping into, using every sense until the feeling of it fills me, and then zoom in on the day ahead of me, visualizing every meeting and task having the best possible of outcomes.
Any planning or prep I may do on paper may be helpful, also, but I find that when I skip these simple steps, my weeks have a way of derailing as circumstances take over.
Always come back to center. But, first, you have to find out where your center 𝘪𝘴.