You can get more done in one hour of quiet concentration than you can in two hours with interruptions. But you must create this during the day, not by staying late or getting in early.
If you want to make sure you have some clear space or time to do the most important tasks, then set up a daily time to ‘have a NIZ’. This is essential. A NIZ – a non-interruption zone – is usually a period of time, say an hour, when your staff know that it is not a good time to disturb you. This leaves you to focus clearly, without interruption on the most important, high quality tasks.
The way you create a NIZ is simple: inform staff and train them that you prefer not to be interrupted at a certain time. Pick the same time each day or give a clear communication signal every day for about a week or two. After a while people will realise that that time is a standard NIZ and you will no longer have to mention it.
Don’t be deceived by the simplicity of this idea. People who have tried this would testify that one hour of uninterrupted time is probably worth two of normal time. You can get so much more done and usually the quality of the work is so much greater.