There are two distinct types of urgent and important activities: Ones that you could not foresee, and others that you have left to the last minute. You can avoid the latter by planning ahead and avoiding procrastination.
Issues and crises, on the other hand, cannot always be foreseen or avoided. Here, the best approach is to leave some time in your schedule to handle unexpected issues and unplanned important activities. And if a major crisis arises, some other activity may have to be rescheduled.
If this happens, identify which of your urgent-important activities could have been foreseen and think about how you could schedule similar activities ahead of time, so they do not become urgent.
Urgent but not important activities are things that stop you achieving your goals, and prevent you from completing what you need to do. Ask yourself whether these tasks can be rescheduled, or whether someone else could do them.
A common source of such interruptions is from other people or children for example. Sometimes it's appropriate to say "No" to them, or encourage them to solve the problem themselves.
These are the activities that help you achieve your personal and professional goals. Make sure that you have plenty of time to do these things properly, so that they do not become urgent. And remember to leave enough time in your schedule to deal with any unforeseen problems. This will maximise your chances of keeping on schedule, and help you to avoid stress and anxiety.
These activities are just a distraction, and should be avoided if possible. Some can simply be ignored. Others are activities that other people may want you to do, but they do not contribute to your own desired outcomes. Again, say "No" politely and firmly if you can.
If people see that you are clear about your objectives and boundaries, they will often not ask you to do "not important" activities in the future.