Colored pencils might help? Plus a practice of manually copying last days open To Do’s to start fresh. I’ve done that for a while and if you finish most but not all of your daily tasks it can help get you into a groove. Getting things done made me proud, with a booklet of activities to look back on. Can’t mix notes in the same book though.
"manually copying last days open To Do’s to start fresh" That's a great idea. I could see that helping a lot with consistency.
Have an indicator for done pages (tick marks in the corner works for me), and then for not-done pages that you need to get back, add those tiny stickies and let it stick out of the page.