Lizandra Vega

In a 2010 national poll conducted by the Center for Professional Excellence at York College of Pennsylvania, "appearance" ranked second only to "communication skills" when respondents named qualities most often associated with professionalism. "How an individual dresses for work can be a powerful extension of his personal brand," notes Matthew Randall, executive director of the CPE. "Clothes, accessories and even the footwear an employee chooses to wear help to reinforce (or diminish) his skills and qualities in the eyes of his employer, co-workers and clients."

Universal dress rules can't be set in stone since what is considered appropriate varies by workplace, field and what is happening on a given day. But if such a tablet were to be created, there's a good chance it would include the following:

1. Modesty is a virtue.

Get noticed for your great work, not your tight pants, overdone make-up, short skirt or cleavage-revealing shirt.

"Nothing undermines how you are perceived in business as leaving nothing to the imagination," says Chris Hauri, founder of Mirror Image, a Chicagoland-based image and identity consultancy.

2. Keep holy the Casual Friday.

Yes, the workweek is almost done -- the keyword being almost. "Casual Fridays are a recipe for fashion disasters," says Lizandra Vega, author of "The Image of Success: Make a Great Impression and Land the Job You Want." Don't jump the gun by wearing your weekend plans, whether that be catching some rays in a halter top and short shorts or cleaning out the garage in your college sweatshirt and cut-offs.

3. Thou shalt wear the right shoes.

Your feet should look prepared for work. Vega suggests skipping flip-flops and other open-toe shoes, while Hauri notes, "High high heels may be fashionable, but not for actually working. Image conveyed: I can't pitch in and do any work because I really can't walk in these things. Want to be a team player? Wear flats."

4. Honor thy leaders.

Not sure what is appropriate for Casual Friday or a client meeting? Look around. "The wisest employees often observe and take cues from the most respected individuals within their organization on what is appropriate workplace attire," Randall says.

5. Thou shalt not steal thy boss's tie.

Keep in mind that taking cues from those above does not mean replicating their wardrobe piece for piece. Instead of coming off as a lemming, find comparable styles, colors and accessories that work for you.

6. Control thy festiveness.

Wearing seasonal colors is one thing, looking like Santa's elf is another. Randall recalls a story about a co-worker who exuberantly over-accessorized her outfits to fit the holidays. "Her overzealousness caused her co-workers to snicker, and she became unofficially known as 'the walking calendar.' Moral of the story: Your workplace wardrobe should enhance your professional skills and qualities, not detract from them."

7. Remember the good book.

Whether questioning what constitutes an acceptable variation of a uniform or wondering about the company's stance on jeans, chances are the employee handbook has the answer. Still trying to decide if you should cover up a tattoo? Seek the advice of a trusted mentor, human resources representative or immediate supervisor.

8. Thou shalt notice what year it is.

Congratulations on taking such good care of your clothing that items from 1983 are still "fine" today. Now put these relics in the Goodwill box where they should have landed years ago. While one need not be a fashionista, looking outdated can give the impression of lacking fresh ideas.

9. Err on the side of caution.

Worried your Casual Friday outfit might be too relaxed or that a bright orange shirt might not be received well by a new client? Avoid the guesswork (and the corresponding nervousness) by making "safer" choices when in doubt.

10. Dress for the job thou wants.

A final tidbit: "My advice for everyone, no matter what age or gender, is to dress for the job you want, not the one you're in," Hauri states. "Unless you're happy with where you are, which is just fine."