First, I will share a story that happened to me at job fair a few months ago....I received the "bone crusher" (see below) handshake by an individual that not only made me wince, but when they went in for the second squeeze, I actually said "Ouch!" I tried so hard to be quiet, but the grip was so powerful and painful that I could not help but to react. The person did apologize and we tried to move away from the awkwardness, but it was just embarrassing on both sides. As an experienced professional, I tried to not let it create a bias, and moved on. That said, this can be very challenging to do, so you always want to be aware of your shake/grip!
If your grip is too hard, weak or "limp", and yes - sweaty- it will leave an impression on most recruiters and that impression could turn out to be a negative one. The reason why is simple. It is another way to gauge you as a person and your confidence level. It is crazy, I know, but think about it the next time you are in a position where you are thrust a hand to shake or you reach out to shake with another individual. You may not realize it, but you are starting to sum up that person based on that specific experience.
So, just a few tips:
1. Confidence is key and it extends throughout your body. Don't be afraid to firmly shake.
2. If you tend to get sweaty (it happens) then discretely dry your hands or wipe them off if possible.
3. Grip the hand - don't grab just the fingertips or part of the hand - nobody likes this one (the Fingertip Holder)
4. Squeeze firmly, not hard or too gentle.
5. If someone has a prosthetic arm/hand, partial arm/hand, or none at all, then take their lead; If there is no lead then don't be afraid to still "shake."
6. And last, but not list least - avoid placing both hands on the other person's one hand (The Glove). That is not necessary.
So now that you are ready - practice makes perfect! Try out your "shake" on a few friends or colleagues and get their feedback.