I use different methods, but the most important one is an old Fujitsu Snapscan automatic feeder scanner that scans pages by both sides at the same time. I bou

I use different methods, but the most important one is an old Fujitsu Snapscan automatic feeder scanner that scans pages by both sides at the same time. I bought that in order to OCR books(destroying them cutting them with a rotary disk saw) long time ago but I use it today for digitalizing all my notes. If you don't care about destroying your notebooks, it is the best solution. I did that with my University notebooks because I needed to access them in work after University and travel a lot so I don't want the bulkiness of carrying around 20 kilos. No need to flatten, orient, color correct anything, tens of pages per minute. Because of the scanner for my own notes I use single sheets of paper and high quality aluminum clipboards and Staedtler 432 M color pens that last for more than a year or intense work. Way cheaper than a tablet with stylus. I digitalize old books today that need special care and could not be destroyed, archival material like diaries from wars. For that I use an array of cameras and a projector and sophisticated software to flatten it. But that is expensive and needs lots of work. If you are interested on that, just google DIY book scanner, but I recommend the automatic feeder scanner if you can.