How to win over a listener with 'hello.'
If you want to make a great first impression, you must pay great attention to the tiny details. Whether in-person or on a video-conference call, here is a set of tiny details for greeting a customer, partner, coworker, etc:
Stand tall and grounded over your feet (or sit up and grounded in your chair).
Align directly to your listener. Square your shoulders to them (or to the screen on which you see them and on which your camera is mounted).
See your listener. Read their face and body language - their current state of being. Are they present or distracted? Are they open or closed-off in some way?
Letting what you observe of your listener inform you, say hello, hi or whatever comes naturally. Focus on the transfer of the emotional warmth of the word(s) to your listener: a) add a little breath to your voice to soften the tone, b) move your voice up and down a lot, c) Express warmth with your face moving its muscles a lot, and d) lightly tilt your upper body toward your listener.
The truth is I DON'T REALLY WANT YOU TO ABIDE BY THE LIST ABOVE. It's not that the tiny details are wrong. It's that, if you approach the skill of speaking as following lists of tiny details, you'll become a robot.
Can you find a principle in the list – a constant truth to the skill of speaking? Adopt just one new principle and it will improve, not just how you say 'hello,' but how you speak in all contexts into the future.