Thanksgiving Friday and sometimes every Friday is casual day at work. It is thought that if we loosen our ties, we will tighten our productivity. Clearly, dressing down was a factor in the very successful dot-com culture that created forward-thinking and innovative businesses.

But outside of the Web-based world, a too-casual appearance can be confused with a too-casual attitude. Don’t let this happen, because appearance messaging can be the defining dynamic that will influence the climb to the top.

We know it is inappropriate to wear a suit and tie to the company picnic but is it inappropriate to wear long shorts and a T-shirt to the office?

Different climates will determine different rules, but the rule of thumb is to dress casual but look serious.

Pull-on pants and logo sweatshirts are out. Khakis with a vintage T-shirt or a polo shirt are in. Miniskirts and midriffs are a no-go but a lacy short sleeve top with a great pair of jeans will always be welcome.

Just remember, you are still dressing for the office, not for a day in the park.

Overdressing on casual day at the office isn’t square, it just isn’t wise. You need to fit into the company culture or you won’t last very long.

The inability to get with the program will leave a negative impression on your boss’s mind.

Keep your shoes polished, always wear fresh and ironed shirts with a great pair of jeans, khakis, or flat-front trousers. In cooler weather, adding a corduroy blazer to jeans will set the casual tone while still presenting a focused image.

Remember, a casual atmosphere, whether every day or once a week, is a gift that should be respected and embraced – and will become another notation in your file as you continue your climb to the top.

Here are this week’s letters.

Dear Jen:

What is the scoop on loafers with designer suits? I work very long days and the soft leather makes a difference. I see them worn in ads but not by guys in the office.

– David, Great Neck, N.Y.

Dear David:

Yes, loafers are in and can be worn with anything as long as you choose the right pair, since they are offered in trendy to sporty to classic versions. If you spice it up a bit and go for a more fashionable loafer, you can be comfortable and still look good with the suit. Save the classic loafer for Fridays or weekends.

Dear Jen:

Over the years I have put on weight and feel much more confident in a three-piece suit. Sometimes I feel like I might be about 20 years behind the times. Please tell me, are they still in?

– Ben, Roseland, N.J.

Dear Ben:

Unfortunately, your instincts are correct that three-piece suits are kind of a fashion-don’t these days. But if the vest acts as your “tummy tucker” and gives you that confidence boost for deal-making, then sport a collar shirt and tie with just the vest. Lose the jacket and replace it with a button-up vest, a sweater vest or even a nice cashmere sweater. These variations look amazing. Not only will they help you become stylish, but you will still cover up a little, too. I bet you’ll notice everyone will be paying attention to your style instead of your few extra pounds.

Ms. Silano Foy is president of eFashion Solutions LLC and has been a consultant in the fashion industry for more than a decade. Readers are invited to send workplace or corporate fashion questions to styleforsuccess@aol.com.