Opening sealed boxes. The contents of the four boxes in 600 AD will be upgraded if you don't open them, so that you can get a better item in 1000 AD. I honestly didn't know this until this playthrough. I'm skimming through a FAQ before playing, to make sure I don't miss anything and it turns out there are a few things I didn't know.
I also do the Forest Ruins side quest in this video? Will I choose the weapon or the armor? See for yourself.
GarlandTheGreat presently has 943,531 views for Chrono Trigger across 102 videos, with his channel currently having around 16 hours worth of content for Chrono Trigger. This is 5.35% of the total watchable video on GarlandTheGreat's YouTube channel.