Are manicures a "must"?

I get this question often. Absolutely not, but clean, evenly filed nails are a must. If you do not have the time or money, take the time to clean and shape your nails.
Here are some rules of thumb (excuse the pun):

All the nails should be the same length. If a nail breaks off, shorten all the nails to create continuity.
Never wear chipped polish
Always apply polish even if it is just a clear topcoat.
Avoid loud colors or frosted shades, designs and paintings on nails
Consider a french manicure so that your nail color will not conflict with your ensembles

if you do not like the look of a french manicure, consider an American manicure which is similar but less stark and more natural in appearance.