Is there a rule of thumb for working out how much time to dedicate to particular people or issues?
As you have spotted, the trouble with using up your time and energy on the people who bleat most loudly and most often is that it distracts you from the totality of what will make you effective in your job. It means you spend almost no time with the competent people who aren't always running to you to solve their problems but who, nevertheless, need some direction from you. Otherwise you'll be managing them by telepathy - never a reliable way of ensuring the right things are being done and in the right way.
Deciding on priorities for how to spend your time requires you to stand back and consider the big picture. What are the organisation's priorities and what part are you expected to play in meeting them? By what means will you be judged when it comes to salary review, bonuses - or even at redundancy time? Considering your major challenges and opportunities will provide you with the perspective by which to judge what the most important areas are for you to be focusing your time.
The next step is to find time to pursue these priorities. That means getting off your back those who use your time non-productively. If an area of priority is being handled by one of those who tend to bring you their problems, ask yourself if they are up to the job and, if not, will they ever be. If they have the potential to make the grade, it's worth spending time coaching them to develop the skill and the will to do the job well on their own.
How you work with these time-consuming people is important, though. If your tendency is to sort things out for them yourself, you are fostering a sense of helplessness in your staff. Being the expert can be a seductive position, but it doesn't breed self-sufficient, competent subordinates.
A useful technique is to state your expectations clearly in terms of the results you want to achieve (the why, the what and the when) and enlist your reports' input on how they propose to achieve the desired result. If their responses show they don't have much of a clue how to do what's required, be sure to build on what they offer as suggestions, rather than knock them down. This requires patience, particularly when you know exactly how something should be tackled and you could do it yourself in less time than it takes to explain it to someone else. If their response is less than perfect, try asking questions to illuminate the issue and start them thinking in the right direction. Explore the obstacles they see so that you understand whether it's lack of knowledge, or fear, or something else.
Agree a date at which you will both review progress, and make sure you follow up. If there has been progress -even if it's modest - make sure you acknowledge it first, before you critique any shortcomings. This is an iterative process that should become easier over time, so that eventually you will need only to explain the results you are looking for and the individual should be able to go off and do it by themselves. If this doesn't happen, it's possible that the person is unsuited to the tasks associated with the job, and you'd be better to move them or lose them.
One way to manage your time more effectively is to handle a number of smaller, time-consuming issues together in scheduled 'surgery' times, ideally held at the same time each day or week. That way, staff know that you will be available to make decisions, offer advice or exchange information on anything urgent. Another advantage is that people know there is competition for your time during 'surgery', so this encourages them to be succinct and prepared when they come to see you.
By reducing ineffective use of time, you will free yourself up to pay attention to the less urgent, but nevertheless important, things that ensure future success for you and for your organisation. Try to make at least one uninterrupted two-hour appointment with yourself each week, at the time of the day when you feel most alert, for quiet reflection on a single, priority topic. If you have someone else managing your diary, gain their co-operation in keeping this thinking time sacrosanct and shepherding more minor issues into designated slots.
Once you've come to realise that your management time is a precious resource, you may find it easier to set some boundaries around your own wants and needs, with the net result that you will feel less dragged from pillar to post by the demands of others.