Training

The most effective way to lower your overhead is to provide routine and repetitive internal training to your staff. The whole concept of "apprenticing" an employee has virtually disappeared with most practice owners vastly underestimate what it takes to effectively train staff. It is an on-going process and often requires the patience of a saint.  

Checklists:

Top dental consultants will tell you that customized checklists (daily and weekly) for each position in your
practice are invaluable practice management tools to keep staff focused on the tasks at hand. Checklists also provide accountability. See here for free Front Desk Checklists  and here for DA Checklists

Correction:

Just because you showed someone how to do something once doesn't mean they will continue to follow the procedures you've shown them. For a detailed protocol see Correcting Employees