Bust a Save

Busting a brain valve trying to decide the best option for a save/checkpoint system in 'Lylian'. I'm thinking the more automated the better, So as the player doesn't need to bust a brain valve of their own in case of forgetting to save on exit or requiring a bail out on short notice (like, if the game just gets way to scary/cute/obsurd/intense/mother calls dinner ready).
So, at this time I'm thinking an autosave on each checkpoint fitting. Now to work on exactly what information needs to be saved...