flow is an interesting one - it's almost like a parallel dimension when you're so immersed in something that you lose track of time and your surroundings. i find that good mental health and self-help books often suggest similar activities that help to realign your thoughts and perspectives such as journaling, being more aware of your senses, and exercises on gratitude.
One book that comes to mind is "The Power of Now" - it's a bestselling classic on mindfulness by Eckhart Tolle. It emphasizes the importance of living in the present moment and letting go of things that do not serve us, which is a very powerful mindset to cultivate!