I've done this as well. Because I was trying to get to that point ever since I got my first iPad I've got a number of different applications for "taking notes".

I've done this as well. Because I was trying to get to that point ever since I got my first iPad I've got a number of different applications for "taking notes". The notepad integration with the pencil however is top notch. I had one that integrated with Evernote and came with a stylus (before the Apple pen existed) and it worked well too, but Evernote lost their way. For me, the ReMarkable2 is actually a bit better for this, only because the drawing is more seamless and the battery life means I can take it camping without worrying about charging it every day. In my paper notebook I use 'manual' doubly linked lists to connect places where I leave and return to a project/note. So when I start a new thing, it goes in the front contents with its starting page. When I come back to it, I write at the end of where I left of "to page->xx" and on the page where I've started up again I write "from page->yy". So that at any time I can find a project in the contents, go to the start, and then walk through all of the pages that have some thoughts or information about that project quickly. The other thing that paper notebooks do well but electronic ones do not yet is flags. I have 'post-it' 5 color flags usually glued/taped to the inside cover of the notebook. So I can add flags to pages with specific things like 'green flag' means business idea, 'yellow flag' means waiting on something before I can continue, 'red flag' means this has an action item I need to do/finish to make progress, and typically 'blue' flags are used to indicate the first 'unused' page in the notebook so I can easily open to it. The 'Makers Notesbooks' from Make Inc have a ribbon page marker that works for this as well.