What do you guys do to get out of your comfort zone while practicing?  I shot terrible today at a 3d shoot and told my buddy I was shooting really well at my house. He said" thats because you were at home and in your comfort zone."  How do you guys mix it up?

i mix it up by shooting as many 3ds as possible

I do the same as eric

As said above, attend as many as you can.  The addition of unknown yardages, terrain changes, shooting in a group of strangers, and only shooting one arrow every 5-15 minutes plays on your confidence and ability.

One thing you can do at home (if you have the time) is to practice only shooting one arrow every 10 minutes (for 30 shots) and vary the yardage from 15 - 30 yards if possible.  Another thing is to get together with the friends that you make shooting 3D on a semi regular basis and just shoot for fun.  This will help with the shooting-in-a-crowd pressures.

More importantly than both of these suggestions is to develop good form, and a solid shot sequence....each component of which should be the same every time (this will take awhile), that you can repeat under pressure.  Then, once it is your turn at the stake to shoot in competition, tune everything else out...it's just you and the target and this one shot.  Take your time, focus, and don't rush it.

Good luck!  3D shooting is addictive and fun....it's even more fun as you improve and get more competitive.

Shoot more 3-D with lots of different people. You'll get used to being on stage and settle down. You'll also realize you aren't as bad as you think and we all suffer from these anxieties.