I have started recording my sessions. And there are a couple of reasons why you, too, should do that.
It helps you remember details
When I’m DMing I have to keep track of lots of things. So I am going to forget small, but sometimes important, details of things that have happened during the session by the time it ends. But, since I record my games, there is no chance I won’t be reminded of them. This way, I can plan my next session without missing anything.
It helps you improve your skills
When I listen to one of my recorded sessions, I always find something that can be improved. I note it down and make sure to keep it in mind for the next session. For example, one time I realized that in one session I wasn’t describing very well the characters’ surroundings. Since then, I have been putting more effort into it.
You can write a session report more easily
If you like writing session reports that’s a lifesaver. You won’t have to take notes in the middle of the session or put effort into remembering what happened afterwards.
You can just keep a collection of your sessions
If you are a perfect DM with awesome memory, the reasons above aren’t that appealing. However, even then, keeping records of your sessions can still have its usefulness. Listening to your sessions can be fun. I would never believe that I would enjoy listening to my sessions that much. A hilarious catchphrase one of your players comes up with on the fly, the occasional inside joke or that critical success or failure that led to hilarious situations have extra value because you were there when they happened.
I use a small audio recorder I got at a reasonable price. The quality of the audio is actually pretty good. I even keep it behind the DM Screen and it has no problem recording everything my players say.
But if you don’t want to buy an audio recorder just for gaming, there is another solution too. You can record the sessions using your phone’s recorder. You will have to find a good spot to place it and the recordings may not have super good quality but it will work. You won’t be using the recordings for a podcast anyway.
Until next time, have fun!