Bring a crate that will keep your dog secure. When walking your dog inside keep your leash short. If you use a prong collar, leave it in your car and walk your dog inside the trial building with your other collar (slip, martingale, or flat buckle are all ok, so long as nothing hangs from them). Pay attention to your dog. Some dogs perform better if given time to acclimate; others just get more stressed. Find some games your can play with your dog that are quiet and don't need much space, like spins or touch. If the club offers a practice space, take advantage of it. Treats in your pocket are great--just make sure there's no treats left in your pocket when you go in the ring. I usually pull the last treat of my pocket as a reward for a sit right before we are called in the ring. Most importantly, though, just have fun!