However, when you consider that Vespers and especially Orthros are variable and lots of changes, it will be impossible for you to anticipate every change (unless you have access to all the service books necessary, like the Octoechos and the Menaia). I would strongly counsel you to divorce yourself from reading along with services and to listen as attentively as you can so it can be imprinted more on your mind and heart. That way, you are praying more and reading less. Just my opinion and I admit, it's one that is not very popular.