One of the most common habits that is also one of the hardest to break is perfectionism. For all but a few roles (e.g. accounting) perfectionism causes a huge hit to productivity.
I read somewhere last year that the best general managers make the right decisions 65 percent of the time, but are constantly monitoring the results of their decisions to enable them to adjust course should they find they erred in their thinking. Forward motion is almost always rewarded more than perfection.
One of the leading causes of the perfectionism affliction has to be our outdated academic system. A student graduating from a top college has been trained for 17 years that 93+ percent accuracy (A grade) is the definition for success.
If you ask most students, they will tell you that the effort to get an A versus a B is significant. It often doubles their work load. This is the same loss in productivity that you find with perfectionists in the workplace.
Perhaps the right target hire is the person with a B average who made the most of college through activities, internships, travel and work. Multitasking is far more valuable than perfection.