I recommend that you write your thoughts in a notebook before going to bed to know what you should work the next day.
Having a starting point is important to check your progress and make improvements.
After 28 days, an activity you do every day will become a habit.
If you don't know what your biological clock is, check out this link: https://www.healthline.com/health/chronotype. By knowing what time it works best, you can use this to your advantage and get work done.
Then turn off your cell phone or mute it. Avoiding distractions while doing a specific activity will help you focus and improve your performance.
Download the pdf I used to organize myself when I was doing my postgraduate degree in England ☞ PDF.