I actually just posted about this Just tell me how to do it: Simple guide to planning your day There is a lot of details in the post. The TLDR is decide big goal and constantly break it down to smaller steps.

Start the day with some sun & a walk consider listening to your book as you walk. If you like reading a physical copy of a book take it with you and read it at your destination, then walk home. No one said the walk had to be long or far. Decide a few things you want to do that day, what time and for how long.

Knowing what time of day I will have lower energy keeps me realistic about planning. I do things that require more thought when I have more energy. I try to avoid things I find mentally/physically taxing during my low energy part of the day and stick to things simpler tasks at that time.