Day one at your new job can be exciting, nerve-wracking, and exhausting all at the same time. As you walk through the doors, remember that first impressions matter. If you think they don’t, read the book Blink: The Power of Thinking Without Thinking by Malcolm Gladwell. In his 2005 best seller, Gladwell reinforces the belief that people formulate opinions in the first several seconds of interacting with someone.

I’ve hired hundreds of people over the years, and I can tell you from experience that Gladwell hit the nail on the head. The first time I meet someone, whether it’s my intention or not, I form an instant opinion of them. Are they smart, confident, polished, nervous, timid, or passionate? It’s only natural for people to feel pressure the first time they meet their superior or new coworkers, but it also sets the stage for how they will handle themselves when they meet a potential client for the first time.

Here are some things to keep in mind for your first day:

Project happiness

Have you ever noticed that when you smile at someone, their instant knee-jerk reaction is to smile back? Smiling will give them a sense that you are thrilled to be there and that you’re excited about the opportunity ahead.

Demonstrate confidence

It’s amazing to me how many young adults new to the workforce fail to shake hands firmly and make eye contact. People want to know that you’re engaged and confident. A weak handshake tells me you’re timid. Looking anywhere other than my eyes when we talk shows me you are either incredibly nervous, distracted, or bored—all are bad. You got the job for a reason. You belong there. Show your new coworkers you are a confident, but not cocky, new hire.

Show interest in your new coworkers

When you are meeting someone for the first time, ask them a question or two. “Where are you from?” “How long have you been with the company?” People like to talk about themselves, and this will give you some time to see how they interact with others. They will appreciate your showing an interest in them right away, versus just thinking about your own situation.

Dress nicely

Every job is different, and business suits may not be appropriate for your line of work. But you shouldn’t show up for your first day looking sloppy. Avoid jeans, T-shirts, and sneakers, at least until you get a sense of what your new work environment is like from the inside. You can always adjust to more casual attire once you get comfortable at the company. However, you should focus on showing people you are serious about making a difference in the firm. Whether you like it or not, your physical appearance matters.

Show up early

The legendary football coach Vince Lombardi insisted his players be 15 minutes early to every meeting or practice. If you were on time, you were 15 minutes late. You should be prompt in all aspects of your business life, but as a first impression, it’s essential. No one wants to see you running through the front door two minutes before you are supposed to start on your first day. It will also give you time to settle in and breathe a bit before meeting your new coworkers.