First thing's first -- jewelry. Rings, bracelets and earrings are the staples of the accessorizer's tool kit. Consider complementing any rings with a leather watch or bracelet on the other hand. Bracelets, whether worn solo or as a left-right pair, work best when paired with short sleeves. Since your wrists will often be resting on a desk, think about avoiding clasp bracelets. Elastic bracelets are not only more comfortable, but they'll avoid bothering your coworkers with the constant sound of scraping metal.
Your purse isn't just a good way to schlep around mints and makeup; it's also the most versatile part of your outfit. Even though your closet may be stuffed with pleather and nylon cases from your last regional conference, consider investing in a smart, elegant handbag. Even a lineup of two purses (one light color, one dark color) can go a long way toward complementing your overall attire.
The versatile silk scarf is always a good accessorizing choice. There are dozens of different ways to tie a scarf, and by spending a bit of time refining your tying skills, pretty soon you'll be able to serve up a scarf style to match any motif.
Shoes are the natural bullet point to any outfit. Whether you prefer pumps or flats, leather is usually your best bet. Black and brown work great for dark outfits, bone and teal for lighter ensembles. Simple and hushed is usually best when it comes to shoes. You might be able to pull off shoes with minor embellishments, but that's going to depend heavily on the rest of your attire.
Your most visible accessory, conveniently, is already attached to your head. A set of highlights, a few minutes with the curling iron or even a barrette is an easy way to completely transform any workplace ensemble. An office job shouldn't require that you put your hair into pause mode. Be open to changing your hairstyle with the seasons. A changing hairstyle denotes an open-minded, team-friendly woman -- both of which are very valuable professional assets.