i just think about doing the skill right and making the correction that my coach told me to make. and right before i go i count to 3 in my head take a deep breth and go. it works for me. i hope i helped.
I always focused on keeping my belly button over the beam at all times. If all other mechanics are correct, this helps you land elements on balance. The initiation of a skill is the most important phase. I would say in my mind, " Good form, correct beginning and trust it." This worked for me. When you train right and can do your routines well in practice, competing should be the same. Don't let fear intimidate you when you KNOW you are prepared. Master control of your mind and your body will do as it's told. The mind rules the body. I hope this advice helps.
On any turns I think "ridiculously straight posture" Before any acro I tell myself, and up- its almost like I have someone pushing me to do the skill. Then when I stick it, I feel justified congratulating myself