How we change what others think, feel, believe and do
The first few seconds of any conversation, the 'hello' part, is extremely critical, especially if you have never spoken with the person before. Yet many people blunder through these moments as they charge towards their chosen destination.
The basic principle is to build the first steps of trust. In a few seconds?? Yes. The alternative is to lose it in a few seconds.
Look them in the eye
When you talk with them, make eye contact, particularly during the greeting. Prolonged eye contact signals either aggression or sexual interest, so don't stare, but do give them a reasonable duration of friendly eye contact.
Make the eyes friendly. Smile and mean it. False smiles do not reach the eyes, so whatever you do, don't pretend.
It is difficult to control your eyes, so the best way is to control your feelings. If you genuinely are interested in the other person, then your eyes will convey this. As appropriate, do some self-talk before you begin to put yourself into the position of really caring. Tell yourself that this is a human, just like you and who deserves your respect whatever else you may think. Smile inside first, let it grow, then project it out with radiant warmth.
Just with how you look at them, you send big messages. You can show and build confidence. You can project authority or other attributes. In fact you will always be projecting something -- the trick is to project that which you want them to receive.
Say their name
If you have been told their name, use it immediately. This both shows that you are paying attention to them and that you consider them important. If you do not know their name, discover it, then remember it.
If you don't already know them, a simple neutral introduction is to say your name and employer. 'Hello, Jack, I'm Richie Bennow from Jemson Construction.' Resist the temptation to immediately dive into product talk. All you will get are objections.
Greeting as promotion
Depending on your situation, you can use the words of the greeting to promote what you are selling or even yourself. When somebody asks you how you are, instead of answering 'fine, thank you', add something about what you want to say, such as 'I'm very well and looking forward to working with you today' or 'Mike, I'm good. I've just opened a new store and folks are flocking in'.
...or whatever the local custom is. Handshakes can tell a lot about a character and can show aggression, assertion or passivity in the first moments of a greeting.
Generally, a firm handshake is best, but not a bonecrusher. Try to match the other person's pressure. If they go limp, don't squeeze hard. If you are a man, be particularly careful when shaking hands with a woman.
Kiss, bow or whatever
Greeting is a social ritual that varies greatly across cultures, both within a country and particularly across countries. In many Eastern countries, bowing is often important, including how low you bow and how often. In other countries hugging and kissing can range from mandatory to forbidden.
If in doubt, watch how others greet one another, though do be careful as a greeting between friends can be very different from a greeting between a senior manager and a lower subordinate.