Contact information for dive buddies- I try to get an email address for different people I dive with and information for shops and boats.
It is a great way to show your experience if anyone ever needs to see it.
I maintain a paper log with basic information and I also get signatures from students in my paper log.
Most of my detailed logging is done by my computer and then I upload everything into Subsurface where I can type in all the details I didn’t have room for in my paper log and I can even attach photos and GPS coordinates.
You will never regret logging a dive but you may regret it some day if you don’t.