Wow, and I thought I was the only one.
I have been flying since the late 80's or so. I was a Sportsman Pattern Aerobatics Champion in 1996/1997 back in New Zealand.
I have flown everything from small sports planes to large aerobatic 3D aircraft and more reciently Jets.
Every time I bring a new plane to the field to maiden I still get the nerves and shakes. For me anyway, it seems like the longer I have something on the building board, the more I shake. It usually only lasts a couple of flights or so till I get to know the characteristics of the plane.
Also, If I have a misshap or scare on one flight I get the shakes at least for the first part of the next flight (No matter what plane I fly)
I posted the above info just to let you know that you don't have to be a beginner to get the shakes.

To minimise them, I have a routine I go thru for each and every flight.
Start up - Taxi out but hold short. I walk to the pilot area. I adjust my hat and sun glasses, flex the mussles in my legs, stretch out my arms and hands (Comments from the p-nut gallery say I look like a starfish when doing this), get ready to taxi out and take off by doing a quick once around the skies for full scale and check the wind sock, get comfortable, take off and have fun!
I know this sounds like a lotand takes a long time, but in reality only takes 2-5 seconds, and it helps relax me.
Anyway, it works for me!

George