Joe Navarro is a former FBI agent who specializes in nonverbal communication, body language, and other fascinating aspects of human behavior. He's written numerous books on these subjects, including The Dictionary of Body Language, and conducts corporate and government trainings through his Body Language Academy. He's also known for training professional poker players on how to identify "tells" and avoid giving them yourself. Here's what he says about handshakes:
I come from a culture where we like to stand close together, but personally, I like to keep people three or four feet away. So one of the ways to avoid violating space, which makes people uncomfortable, causes psychological discomfort, is to, when you first shake hands, you reach in and you shake the hand. And rather than just remaining there, take a little step backward and assess what the other person does. And one of the things you'll find is if both of you take a step back, then both of you need that little bit of extra space. If the person moves towards you, then perhaps they come from a culture or they have a preference for standing closer. And in that case, what you may wanna do is just angle your body a little bit so you don't feel like they're as close to you as they may be.