Failure to Delegate. Many business operators, or mangers for that matter, don't fully utilise their human capital. Actually I think the term "human capital" perhaps to change our attitude should be referred to and thought of as a pool of "human potential". The old problem of effectively delegating tasks still seems to be badly handled by many. Although initially time consuming, in the longer term delegating tasks will free up vast amounts of of time and create opportunities for other vital forward thinking to activities. Delegation of course will also allow for much more valuable engagement with colleagues and staff. More here if you want it: How to Delegate
Poor Prioritisation. Anyone in business simply must prioritise their activities by separating things that have to get done from those that should be done, The problem of course is that often lots of tasks come up that are easy, particularly in the "should be done" pile and we are tempted to do what is easy rather than that which is important. Setting Priorities, more here if you want it: Setting Priorities See point 8
Lack of Streamlining. Great time management gains can be made by streamlining various aspects of daily workflow. Some formal review of 'standard' procedures needs to become a regular part of the work culture. Outside partners such as service providers, suppliers and customers can be enlisted to help with process improvement if you are not into a full blown total quality management approach. More on Management here, if you are interested: Management Short Course