This may seem like a small tip, but if your nerves tend to create 'sweaty' palms then the following
will be invaluable to you in creating a more positive first impression! Running cold water on your wrists for a minute will help you keep your palms dry for roughly 10 minutes. This is great when you are able to access a rest room just before your meeting.
When in doubt about the availability of a restroom though, consider putting Antiperspirant on your hand. It is designed to control underarm sweat and can certainly help control a damp handshake too!