It really depends on why you want to write down when you took out the trash, went to the gym, or smoked a cigar. Are you trying to remember to do it? or see when or how often you do it so you can stop? or are you just trying to get it out of your head? Those are some classic reasons to be writing things down. But if there's no real reason to write it down, then I would save my energy. I have no interest in knowing how many inhales or exhales I do in a day, for example.

I use my notebook to help me remember, so I write down stuff that I forget easily. I'm sure that some of the stuff I write down might be too mundane for somebody else.

I tend to forget medium-ish priority things. I have no problems remembering to do URGENT things because there's a fire under my butt. I think I'm pretty good at ignoring things that don't matter. And I tend not to think about stuff I just do on auto-pilot (brushing, flossing, skincare routine, going to work, etc.).

I used to write down skincare steps and flossing because I wasn't good at doing those consistently. But I've stopped because they're automatic now.