People ask me all the time how I can produce so much finished audio in one day. It varies of course depending on how the copy is written. The real secret is to rehearse a lot before you step into the booth. I had done over 50 plays by the time I was in my mid thirties so I had a habit of rehearsal. I treat my recording sessions as if they are readers theater where everything is "live." Everyone is different of course. There is no right way or wrong way. It just depends on how you prefer to work
I like having my approach all worked out so the number of retakes are reduced and consequently the editing time is a lot less.