Creativity, it's said, is 5% sweat, 95% presentation. Being self-employed or owning and running a small office teaches you a lot about customer relations. It also deprives you of the working model for office/client/employee procedures you would find in a typical working office.
When I took my studio personal and rented my office out to another firm in a similar business, they asked me if I would "mentor" them some about customer relations and office management. The glow of the new digs wore off quickly so the mentoring never happened. But I am an occasional customer and our interaction led to some thoughts about customer service.
When your client has an impossible deadline and you deliver on time — then the client doesn't show up for days, even weeks to pick up the work — you ask yourself, "If they did't need it that badly, why did they have this impossible deadline?"
One explanation is the timing of the phone call. Say the job is done, on your counter, and you call and let the client know it's ready. Now they have to wrap that task into whatever else they have to do just as they had to wrap their deadline into their entire list of obligations. New information often makes deadlines flexible, sometimes making them non-existent. So the urgent job sits, along with the deadline, gathering dust.
When you are creating something for a client's tight timing, letting them know the job is definitely going to be on time, ahead of time, gives them the opportunity to fold your work into their project. Giving them a heads-up a day prior to delivery can make you look like a hero and strengthen your relationship with your client.
Just make sure you deliver when you said you would.