If your grandma was like mine, you might remember her saying a thing or two about the importance of "keeping up appearances." And if you were a kid like me, you probably rolled your eyes more than a few times.

But the thing is, granny might have given you your first solid piece of business advice.

Despite a more casual business culture in which we Uber our way to a meeting and wear ripped jeans in an incubator, the way you carry yourself speaks volumes about you--and whether other people take you seriously or not.

This is much more than just your makeup or clothing, or whether you remembered to drag a comb through your hair. You could be dressed head to tail in Gucci, but if you shrug your shoulders, shuffle your feet, and avoid eye contact, you'd be better off in a garbage bag. And if you stand tall and instill confidence with your handshake, but your voice is barely audible, you'll lose important points as well.

Let's talk about posture

How do you walk into a room, onto a stage, or out of a meeting? If you also remember grams telling you not to slouch, she was giving you some good advice. Yet according to public speaker Nick Morgan, how you carry yourself is more subtle than remembering to stand up straight. We're being read all the time by the people around us, mainly unconsciously, and what we don't say with our bodies speaks much louder than words.

Body language gives continual clues as to what other people think about us and reveals what's going on in our minds as well. Most people decode emotions through gestures. So, it may not be what you say but the way you say it that counts. Without realizing it, you can confirm yourself as the "top dog," provoke an argument, close a deal, or completely destroy your authority through your unconscious physical cues.

Medical studies continue to prove that you need to stand tall, sit up straight, and practice good posture if you want to optimize how you look, feel, and perform and even reduce symptoms of depression. According to Bill Schultz, founder of Alignmed, "Good or bad, posture has a primary effect on physical performance, aesthetic appeal, fatigue, injury recovery, blood circulation, oxygen flow, digestion, inflammation, pain, depression, and the power of the immune system to heal." Pretty serious stuff.

If you thought that slouching your shoulders was just a comfortable way to sit, it might alarm you to know that, left unchecked, continued bad posture can evolve into a chronic disease. "Make yourself aware that your posture is your closest companion from birth to death," Schultz advises.

One of the best ways to go about getting your posture in check, he says, is to create a simple form that documents the number of hours you spend sitting throughout the day. Then design a standing and moving strategy that will equal the hours spent sitting. This should include pacing, stretching, walking backwards, and standing while talking on the telephone. Not only does bad posture have a negative impact on your health, it doesn't help your job prospects or chances of wooing an investor, either.

The language your body speaks

Body language is paramount to communication and relays a whole manner of messages before you even open your mouth. Just think about the last time you were in a waiting room, doctor's surgery, or elevator. You probably leaned against the wall, maybe crossed your legs or let your shoulders drop--if you were alone. Yet, as soon as someone else walked in, you probably (unconsciously or not) stood up straight and adjusted your pose.

Retired FBI agent and best-selling author of What Every Body Is Saying Joe Navarro confirms that it's normal to adjust your stance in front of strangers, and is actually genetic. "Your brain doesn't want you to be off-balance around strangers," he writes. Thinking way back to the hunter-gatherer age, staying up straight gave our ancestors the power to prepare for an attack or to run away at full speed, if necessary.

A common slide in body language for most people, especially those who spend plenty of hours behind a desk, is to slouch their shoulders. But again, rather than just a bad habit to get into, slouching your shoulders is a sign that you're stressed or feeling overwhelmed. It's also unconsciously sending out the message that you're defeated. Improving your posture and understanding your body language is crucial to lifting your confidence.

Don't underestimate the power of your clothing

Another, perhaps simpler way, of giving your confidence a boost is by paying attention to what you wear. It's a lifelong task trying to build up your confidence, especially if it doesn't come naturally to you. But dressing to impress can give you the added shot of confidence you need when looking in the mirror to kill that presentation, go after a mega investor, or even just ask for a pay raise.

Make sure you dress for your body type and wear clothes that fit well, as ill-fitting shoes will make you shuffle. They'll also stand out a mile away--how many times have you seen a woman limping along the street on a pair of wonky heels? Not only does that contribute to bad posture, which impacts confidence, but it's also not sending out the best message about yourself. Dress to the occasion, as well. Research actually proves that the clothes you wear have an effect on your performance. So, be sure to iron out the details (and the fabric) before you step into a meeting.

The way you speak matters

Quite a lot, in fact. Your conversations, formal or informal, and performance in meetings and presentations greatly impacts other people's perceptions of you and can even erode your credibility. Communication errors, such as mispronunciation, a harsh accent, or using terms of endearment in an inappropriate place, can all put people off. Avoid profanity at all costs in the workplace. Not only does it create an uncomfortable environment, it may also be construed as sexual harassment.

Your choice of words, not simply avoiding bad ones, is also critical. According to Scientific American, "a wealth of unique insights into an author's mind are hidden in the style of a text." While language and speech training can be taught, often when people try to force themselves to speak a certain way, they select the language they feel will be most appropriate. This can often lead to a delivery that sounds unnatural and turns an audience away from them.

Like granny said, the way you carry yourself speaks magnitudes. Especially in an increasingly fast-paced age where people make continual shortcuts and instant judgment calls to save time. How you sit, stand, dress, and speak can be a thousand times more valuable than a Harvard qualification. It tells a story. Which speaks volumes.