Every page or section (in a page) has checkboxes for the notes or a way to tick it off as done. I keep checking them off when I’m done reviewing them or if they are transferred digitally or “consumed” with meaning and context. Sometimes, a page lingers longer (working on it), and I need to return to it a few times; I use commonly available tiny stickies that stick a tad out of the page.
So, my finished notebook will not just have notes and sketches but will always have a tick (done mark) at the top of the pages and no stickies sticking out.
I’ve also found that if I need to remember anything in the next minutes or hours, I set a timer[1] on my watch. Instead of taxing my brain to remember something, it is easier to jolt back when the timer kicks in.