I do 4 takes of everything I record....I have a great setup to ensure that they are all pretty evenly matched volume-wise...I then cobble together a final take from all the best pieces. Rarely does an early take make the finished product....it's mostly about confidence....by the 3rd or 4th take, you're usually pretty confident...
 

I call this "Red Light Syndrome".
 
The only way to get "beyond" it is to keep moving forward.
You'll ultimately become less anxious during the process.
 
As has been mentioned, loop recording can help.
There's a point where you're more "locked-in" with the desired feel.
For me, that's usually some mid-point in the takes.
On early takes... I might not be totally focused.  
On later takes (at least for me)... the part can start to mutate into something else.
 
Aside from technical perfection, there's also the emotional facet.
Too many takes (too much analytical thinking) can squash the emotional impact of a track.

Sidroe
I can not tell you how many times I have asked the artist just to run thru the take for me to get levels and warmup a little. Little did they know I record every time they play or sing just because you never know when something magical will happen just on that one verse or chorus or solo!

This has been my standard M.O. for the last 20 years.

Only works a couple of times per artist though, they get wise to it.

There is a story about Tony Banks from GENESIS.  He too had stage freight when it came to recording.  Not when the entire band were playing but when it was time for him to do overdubs.
 
The intros to FoF and The Lamb are some examples.  The engineer would fool Tony into thinking the take was just to check the microphone placement and settings.  In this mode, TB could make it all the way through the take. 
 
So, fear not, you are in great company. :-)
 
Jim

Thanks to all for the good advice.  I think I'm going to have to look into loop recording. 

Capture Last Take As Recording. This is a cool thing not just for recording without being consious abt it. But also in many other ways. Think about the times we hit the play button and thought we are recording. Wish sonar has this. https://ask.audio/article...ing-for-midi-and-audio You wont get nervous anticipating the recording if you practice capturing them from playback.

here I have started a feature request on this do vote http://forum.cakewalk.com...ecording-m3430634.aspx

SimpleM, Gee, I hope none of the guys and gals I work with read this!!! I set up the auto punch-in, punch-out for the entire song. That way, I can even leave the room and they don't see me hitting record!! It's amazing how that little trick has worked so well over the years. Oh,well! The cat's out of the bag now!! LOL!!

Hey hey,
 
Worked my way through similar issues when I was younger, albeit in a round-about sort of way. I noticed early on that the RECORD light is a blessing really, much like a live performance it screams "If you're gonna do this, all you can rely on is what is in your hands and mind NOW". After much practice you'll see that this pressure really pushes you to the limits and often leads to surprisingly cool results just as long as you can learn to 'live the moment, surf the now...". Its a skill like any other, being spontaneous that is.
 
Secondly I'd recommend checking out some 'demo project' recordings. These are the 'raw sketches' that lead to epic studio recordings. They're loose, ragged, sound entirely imperfect and have little concern for anything but sheer creative bravado - be so blunt and to the point that even those that dont like it will have to admit you / the band / the song are really going for it. Once you are content to show ideas through sketches / demos this will take all the pressure off making it sound like a produced CD. Its just a means of communication then, get the melodies, harmonies and rhythms clear and you're set.
 
Hopefully you can see how the two things above come together. So much of confidence is getting things out the way so that your true self and skills can breathe. Relaxation and focus create the bucket, your natural creative spark will flood and thats when it gets interesting.
 
Now go improvise some music! :D

I practice with record on.