Running a business is tough. You're tired, stressed, and that pair of trousers you threw in the laundry basket yesterday is probably going back on you tomorrow. Getting stuck in a fashion slump is easy when you're busy, but let's face it--what you wear and how you present yourself can make a lasting impression on your customers and employees.

To spice up your office wardrobe, we found a team of style experts to put together an easy guide to business-friendly fashion. From casual office wear to client dinners, we've got you covered with Entrepreneur's spring fashion guide.

Men's Styles

Suits
Say goodbye to loose, baggy cuts and broad shoulders. This year's suits create a narrow silhouette that's sharp and modern-looking.

"Business looks are more fitted, but not to the point of making one feel body-conscious," says Mario Bisio, owner of luxury apparel store Mario's.

Men's Fashion - 1Jeff Horowitz, co-founder of DressMonkey, agrees. He cites the following three trends to look for this spring:

  • European cuts: Unlike the boxy shape of American blazers, the European cut has a sharper shoulder, narrower arm and nipped waist, making it an ideal fit for formal blazers.
  • Narrow lapels: For a slimmer, more modern fit, look for a suit with a narrow lapel. These lengthen the torso and add height; they also pair well with slimmer ties, which are back this season.
  • Side vents: Vents add functionality and ease of movement to the traditionally rigid structure of a blazer. While American blazers generally rely on a center vent, the European style of side vents covers more while bending or sitting, thus keeping a more crisp appearance.

Business Looks for Important Meetings
When in doubt, a dark suit always makes a sharp, professional statement.

And while solid colors rule in the boardroom, Bisio says a faint check in the shirt or subtle stripes on suit coats are suitable light touches. He adds that this year's look for ties is a solid color or subtle print.

Men's Fashion - 3Casual Looks
Thankfully today's office attire doesn't necessarily mean a suit and tie.

  • Go sharp. For a polished casual look, pair a crisp, collared, button-down shirt with a pair of dark denim jeans and a casual leather, slip-on shoe. Don't just throw on any pair of jeans, though; find a pair that's tailored to your body shape and wrinkle-free--which might mean dragging the dreaded iron out.
  • Go retro. "Male professionals should take advantage of the return of the cardigan," says Erica Easley, author of Rock Tease. Easley suggests jewel colors such as red or emerald green, which play nicely with traditional office colors such as gray, black and navy. He adds that slim cardigans--particularly ones with a luxury logo, like the Lacoste alligator--are extremely hip this spring and pair well with tailored trousers.

Men's Fashion - 2Evening Looks for Client Dinners
Client dinners are less formal situations that allow you to be more self-expressive in your clothing choices. According to Horowitz, the predominant spring fashion trend is personalization. Young professionals, in particular, are eager to wear something that says, "I'm different."

  • Go bold. "Express yourself by choosing a bold color or print on the inside of your blazer such as red, white silk or printed designs based on Chinese textiles," says Horowitz. "Try pairing a neutral gray or camel blazer with a shirt in one of the neon colors that are back this spring, such as orange, yellow, green, blue, pink and purple."

Shoes and Accessories
Here's a little secret your female counterparts have known for years: Shoes can make or break any outfit. Invest in at least two pairs of expensive, well-made shoes--a pair that's dressy and pair that's more casual. A good pair of shoes can pull any outfit together and make you look sharp and orderly.

When it comes to choosing shoes and accessories, follow these three rules:

  • Pay attention to details. Do your socks match the trousers? Does the belt coordinate with the shoes? Does the pocket square match the shirt?
  • Lighten up for spring. Spring's lighter color palette calls for men to trade in their basic black shoes for brown suedes.
  • Pull it together. If there are belt loops, always wear a belt.

Hair
A good haircut is an investment in style that's worth making.

"To me, it's always interesting when I see men with the mentality that a haircut should be $15," says Julien Farel, celebrity stylist and owner of Julien Farel Salon. "You're going to spend a lot of money on your suit, a lot of money on your car or your house, and then at the same time you're going to be cheap on your hair?"

Farel believes the most important accessory a man can have is his hair.

"You're going to have it for the next 30 days. If you don't like a suit you can change it the next day and it's OK--you don't have to wear it again. For the hair, you can't. You're stuck. Truly, most of the time, you'll look like you have a $15 haircut."

To change your look, find a professional stylist who will give you a cut based on the shape of your head, neck and body. Get the most out of your money by getting a haircut that can go both ways: sleek and conservative during the day, and spiky and trendy for after work.

Women's Styles

Women's Fashion - 1

Business Looks for Important Meetings
This year femininity will rule the boardroom.

"Although a smart black pant suit will always carry confidently, modern dresses with jackets reclaim a place in the boardroom," says Mario Bisio, owner of luxury apparel store Mario's (www.marios.com). "Rounded club collars and shorter, three-quarter sleeved jackets bring a refreshing change to the menswear cuts that have predominated women's business attire."

In addition, here are two more trends to look for:

  • Wide-leg pants are the answer to last year's skinny pants trend. Opt for khaki or linen trousers and balance out the look with a fitted double-breasted jacket or oxford blouse.
  • High-waisted pencil skirts are a chic way to bring the high-waist trend into the office. Details like buttons or belts will make your waist look smaller and your stomach flatter.

Women's Fashion - 3Casual Looks
Business casual is not the same as after-work casual. Leave the jeans at home and opt for a comfortable yet pretty dress, instead.

Thankfully, this year's dresses are flattering for just about any body shape. Look for a sleek, A-line dress or shirtdress in a solid color, or a wrap dress in a bold print. Opt for a dress with an appropriate sleeve length, depending on the season, and a fabric that isn't too clingy.

Pair bold colors such as yellow, with classic black and white.

Evening Looks for Client Dinners
"Black is your friend," says Nicole Williams, founder and editor-in-chief of WORKS, a career management brand for women. Supply your wardrobe with black staples such as pants and three-quarter length jackets and skirts, which are clean, classic and always look sophisticated.

Women's Fashion - 2"Basic black pieces can also stretch your clothing budget, because they endure through changing seasons and trends," Williams says. "When you're dressing for a full day of work and cocktails, you can use black basics to take you from day to night." She also suggests swapping your button-down shirt for something more bare and colorful, and adding a pair of earrings and strappy shoes.

Shoes and Accessories
This season's shoes come in a variety of bright colors and bold prints, allowing you to dress up your basic office pieces with a surprise splash of color. Try pairing a bold-colored pump such as red or yellow with charcoal trousers, or an animal-print ballet flat with black pants. Also look for metallics in varying shades to add a fresh new twist and compliment hard-to-match colors like navy and purple.

Women's Fashion - 4Whether you're building your wardrobe or simply looking to update your style, follow these basic commandments of style from Nicole Williams:

  • Restrain yourself. Never let your accessories wear you. Big, chunky jewelry can look fantastic, but limit yourself to one key piece. Wear one or two rings, max. And choose jewelry you really love; it's a great way to develop your signature style and express your personality. Jewelry with a story--your grandmother's earrings, the bracelet you bought to celebrate a milestone, your engagement ring--is beautiful and often becomes a conversation starter.
  • Invest in accessories. Think about it this way: You're not going to wear the same pair of pants all week (one would hope), but your bag or briefcase is a constant companion. Clients, employees and colleagues all notice what's draped on your arm. Invest in a quality piece that reflects your style. And in this age of laptops, cell phones and PDAs, a bag that will carry both your purse and your hardware is a lifesaver.
  • Focus on your feet. There's nothing like killer heels to make you fell confident and powerful. You don't have to buy stock in Manolo Blahnik, but a great pair of shoes can make all the difference in your look. From a fabulous stiletto to a gorgeous pair of boots, your footwear is the finishing touch. Just make sure your footwear is polished and clean--a detail that people really do notice.
  • Sweat the small stuff. We're talking fine details--shave or wax your legs if you'll be wearing a skirt. Take a hard look in the mirror and if your upper lip needs waxing, by all means, do it yourself or have a professional do the honors. Make sure your eyebrows are shaped, waxed or plucked so they open your eyes. Keep yourself looking polished. People don't necessarily notice if you're groomed, but they definitely notice when you're not.

Hair
In the business world, hair is your most visible accessory, so it's important to get a cut that fits the image you want to portray.

"There's really no one 'hairstyle' for 2008," says Julien Farel, celebrity stylist and owner of Julien Farel Salon. "A hairstyle is about honing the best of your personality."

Here are two of Farel's favorite ways to get office-ready hair that's young, elegant and fashion-trendy:

1. For long hair: For an easy, classic look, comb a gel spray through your hair and create a very long, low part. Pull everything into a low ponytail and use a flat iron to smooth out the ends. End with a finishing spray for shine to create a very runway look.

2. For short hair: Get a signature haircut. Go for a short bob with bangs, like Katie Holmes', or a trendy bob like Victoria Beckham's. "A lot of women, even as executives, copy these haircuts because they want to still look sleek and sexy, even though they look professional."