Book Covers: Do it yourself or have it professionally done?

My feeling is that sometimes, actually often, writers are their own worst enemy when it comes to choosing or creating their own book covers.  Event he best writers may not have developed the visual senses that professional designers have. 

For Noir Nation and Bare Knuckles Press books we have had better luck using professional designers. Anyone looking for a professional and eye-catching cover for their book or eBook should try Butterflies & Hurricanes (http://www.butterflies-hurricanes.cz/) an excellent design firm in Prague that has done some wonderful covers for a number of our books for very reasonable prices and they are used to working from overseas.