Black is elegant and chic; black is slimming; black looks good on all skin tones; black looks good with all hair colors, black looks as good on men as it does on women. The dress code makes clothes buying and getting dressed in the morning easier. Black, however, can also be one-dimensional and boring, and while it may seem easy to dress in all black.
On the fabric note, make sure the fabric selection is season appropriate. A black wool dress will look fabulous in the fall, but out-of-place during the summer. Silk and linen make it easier to pull off the all-black look during the warmer months.
When putting together a black-on-black, fit becomes even more important. Take advantage of the fact that black is slimming and have the clothes be more fitted and flattering, rather than shapeless and drab. Add interest with accessories. Bold, colorful jewelry becomes the statement piece of your outfit. For me, colored stiletto heels are the go-to shoe with any black on black outfit. Make your outfit more dressy or casual with the simple change of lipstick color. A LBD can go from day (with a light pink lip stain) to-night (with a bold, deep red lip) seamlessly.