I use a microcassette recorder, with a prompt list taped to the front. I record the variables in order as reminded by the prompt list, and can then free form record after that.
I am sure that there are better digital voice recorder, but my old school analog tape recorder continues to work for me.
I transcribe to a lab notebook to sort the n, from n-1 from n+1, and transcribe in detail to the back of a contact print. Having neg holders filed to notch code the holder ID onto the film image really simplifies things with this method.