I don't know how "substantive" this is, it's not directly political and it's not at all partisan, but it's a subject near and dear to me, and I think it's something to think about as you go about trying to influence people so I am posting a (rare) diary about it.
I was introduced to a person tonight and as usual, I put out my hand to shake hands with him. In less than 5 seconds, I was thinking "arrogant bastard!" and I will explain why below...
As I reached out and he reached out our hands approached and as my fingers brushed his palm, he clasped his hand. As a result, he had my fingers enclosed and gripped them and gave them a hearty shake. He probably thought, "A cold fish." as I thought, "Arrogant bastard."
As I see it (and I expect to see lots of contrary comments), one should wait until the webs between the thumb and index finger meet before each participant in the handshake closes. Even if the two hands are of different sizes, unless you (or the other participant) are Andre the Giant, the odds of clasping hands as opposed to "milking fingers" is greatly increased.
It's a small thing and may not even be a teachable thing, but I see it as the difference between the meeting of equals and an "I drink your milkshake" attitude toward the world at large.