When I first began my journey into Cardistry, I performed for friends, relatives, family members, etc. I was still nervous - my hands visibly shaking.
I couldn't go out on the streets to perform - I was way too nervous to walk the streets of Vegas by myself at the age of 13. I persuaded a friend of mine to get into flourishes/magic so he can tag along (trying to psych myself into thinking it was more of a night out having fun rather than a training session - worked pretty well!)
We started having fun with it and bugging people on the strip of Las Vegas and many of our would be spectators would reject us for reasons unknown - or the fact that we were 13 year olds who wanted God knows what could have had something to do with it.
Our rejections would soon fuel us to get somewhat frustrated and start approaching people with a different mindset. Our nervous energy was channeled into presentation and approaching people the right way - which took a load off the stress of actually performing. Eventually we performed for so many people inside and outside a variety of Casinos/Shops, we felt somewhat comfortable in our skin.
That period of forcing ourselves to perform prepared me for the future. I feel once I got older, that fear/shake was also outgrown but not without a little effort of course.
Today, I become anxious, excited, and jittery to perform but I love every second of it. The only time I experience shakes is if I'm performing for a large group of people, doing a difficult Cardistry move that usually involves balance, and can hear a pin drop... but I'm working on that! Always room for development. If one does not get nervous or excited when performing, he/she should most likely reconsider another occupation.