Don’t be overconfident: Do not show a grin, snarl or grimace. If some work or project is given to you, then don’t grin, or seem overly proud; just put your head up with a very slight smile (or anything else that makes people realize that you are okay with the work and the responsibility). You can also show this confidence at home, work or even on a date.
Pull out evidence when talking: Bring out factual information–citing a quote, offering, bringing forward evidence or support–for your position. It will influence the person to whom you are telling a quote. But these examples must be related to what you all are talking about. Not trying to do so will just make you appear to be uninterested in the conversation.
Don’t get overly emotional, proud, hurt or angry: Even if it’s a funeral, or your friend’s Nobel acceptance speech, keep things simple, and go for a firm handshake to congratulate each. Stay silent at funerals of acquaintances or distant relatives, with no obvious tears rolling down the cheeks; otherwise people may think that you are way too emotional to act professionally in all circumstances.
Learn to keep a promise: When you make a promise to somebody, then make sure you keep it. Doing this will make the person think that you are reliable and honest, a trait which will boost your professionalism.
Be good at what you do: If you have several skills or talents, be best at it and never ever try to imitate others. You must always have a great deal of competence so that others will likely notice your professionalism.
Be respectful to others: Be it rich or poor, a CEO or regular staff, your grandpa or the garbage collector, you must respect everybody that you encounter. You must respect all jobs and talk to everybody with equal respect. Slowly, when people start noticing this trait, you’ll be respected.