I have recently realised how important taking down notes is for me. I jot down notes all the time to my non-ruled sketchpad from Muji, and use Drafts (great app!) in my iPhone and iPad. I also speak to myself and my Zoom recorder.
I also make thumbnail sized prints of my photos and paste them to my sketchbook and carry it with me always, it’s great way to arrange images into a sequence and then return to this thought pattern.. This little trick I learned from great Eric Kim’s Youtube Channel.