What if you were your client for one day?
You cannot ask for him doing the same, but it could be a good practice to try (just for one day) to look about your tasks and deadlines as if you were your client, paying for your time.
Think about that when you go out for a break, of a coffee, of any time you write “we are working on this”.
Think as if you would be answering yourself. This is good excercise to understand how your actions and behaviour is actually being perceived by your client.
Of course you are thinking “what about him…! He should either!”.
Well, then think your customer knows what you think about him when he bugs, he perfectly knows 😉