Like many I have talked to, I started with a compact 64 page, 6"x4"x.25"
journal, used it for about 3 days and never wrote in it again mainly because I was too busy living life to actually stop and record it. Meeting and talking and observing other people always took priority over writing down memories of the past.
I still recorded my thoughts, feelings and memories but I did it electronically and usually in the morning while walking by myself. I either dictated it on my iphone in the "notes" app that comes with all iPhones or I recorded my previous or current thoughts/feelings/memories while walking and shooting video which of course also has an audio track. I had a tiny action video cam with lot's of high capacity (128 gig) micro SD memory cards with me that take up very little space. The videos use lots of memory but are the best because they capture your voice well AND the natural sounds of the environment around you plus the visual component. Walking and talking and taking video all at the same time was an efficient and effective way of multi-tasking while making few compromises. It's so much richer to review these videos than to read my journal notes. I could also just key-in with my thumbs a traditional journal entry using the "Notes App" when in a situation where talking out loud was not appropriate. For the video to be "useable", you will need something with good stabilization like this
Sony or
GoPro. You will also need to practice with it before your trip to refine you technique of walking (and pointing the camera with the sony since it has no view finder but can be ordered as an extra). Video cameras require different batteries and battery chargers which add weight and complicate things.
You can also video w/audio on an apple or android phone that has a good electronic stabilization feature and supplemental micro SD memory cards that can be exchanged when they fill up (android only). The stabilization on these phones is not as good as the video action cameras. For super smooth professional results while walking, you will need a 3-gimbal
stabilizer for the phone or action camera but these are bulky, more money, fragile and require more batteries and/or charging cords. A buttery smooth video of which I have none is such a wonderful thing to watch and a shaky, poorly aimed video can make you physical ill to watch...but you will still have the audio.
The simplest and least expensive technique for making a video to record your thoughts and take in the natural sounds and stunning scenes of the camino environment is to stop moving while recording. Use the video function of your phone along with this tiny
tripod to hold your camera so it captures the scene you want and then start recording/talking. Change the view and talk some more etc... It's not as efficient as walking and talking so you will lose a little time over the course of a day but it's time well invested for a pleasant viewing experience when you get home and watch/listen to, your videos.