Apparently there is a guy two of my coworkers used to know who, when you offered your hand for a shake, he would turn it into a bro shake and say “top shape!” (He’s Quebecois. It’s an expression there.) It became a bit of a joke. Because you shouldn’t do that.

When someone offers their hand to shake, you should shake their hand, warmly, firmly, and without embellishment.

We talk a lot about first impressions around here, and the handshake is a big part of that first impression. A bad handshake can turn someone off completely, while a good one can convey that you’re friendly and confident. Doing it right is not difficult, and yet so many people get it so wrong so often. We’ve all shaken hands and been left thinking “What on Earth was that???” Or are you the guilty party?

It’s time to learn once and for all.

Here are the dos and don’ts of the perfect handshake.

1. Wash your hands. There’s the tale of the hiring manager who saw a man walk out of a men’s room stall and leave without washing his hands. The man turned out to be the hiring manager’s next scheduled candidate to interview. “Sure enough he reached out to shake my hand,” said Chris Lawsom, CEO at Eli Group. “I told him that I had arthritis, so I was unable to shake his hand.” Obviously the candidate did not get the job. Even if nobody’s looking, washing your hands is always the less disgusting option.

2. Dry your hands. Make sure your palms are not sweaty. Your hands might sweat when you’re nervous, or you might just be prone to clammy palms. Carry hand sanitizer and paper towels, if you tend towards stickiness, and keep your hands as dry as you can.

3. Don’t extend your hand as you walk across the room. This looks a little overeager. Wait until you get there. Then offer your hand.

4. Extend your hand with the palm sideways, not facing up or down. Up is more like “Gimme five,” while down says, “Kiss my hand. I am a princess.”

5. Smile and say hello. Introduce yourself – if no one else is doing it – as you offer your hand.

6. Don’t give the dead fish shake. Like you’re dipping your hand in tepid water. Or you know that person whose hand just sort of sits in yours while you do all the work? Don’t just let the person grip your hand while you do nothing. That is so creepy.

7. Meet the hand palm to palm. Don’t just hold the fingers.

8. Grip firmly but not too firmly. Some people overcompensate with the supergrasp, but remember that someone might really have arthritis, or a broken finger. Nothing ruins a first impression like causing someone bodily pain.

9. Shake up and down between one and three times. Or the time it takes to say “Nice to meet you.” Don’t let go too early, or it will seem too perfunctory. But between 2 and 3 seconds is more than enough. Some people on the internet say “five seconds” but the internet is crazy. Try holding a stranger’s hand for five seconds. See? That’s way too long.

10. Save the four to five pumps for someone who just won an award. It can be longer when you’re saying “Congratulations!” or for someone you haven’t seen in over a year. Whatever the situation, “The important thing,” says Workopolis Editor in Chief Peter Harris, “is to always be moving. Otherwise you’re just holding hands.”

11. Use the double-hand clasp judiciously. The move in which you use both your hands to briefly hold the other person’s hand may be used sparingly, as in with the above-mentioned person you haven’t seen in a year, or with someone you are particularly chuffed to meet.

12. Don’t wipe your hand on your pants after you let go. It can be tempting. But don’t do it.

Now go out there and shake some hands.