Bouncing around classes and trying new options is a great way to keep your mind and muscles guessing; variety helps prevent plateaus as well as boredom. How do you ensure your first workout is safe and fun? By telling your instructor it's your first time. (Also, be sure to note any injuries and whether you're pregnant.) You want your workout to be tough, but not unbearable, and this simple-but-often-overlooked step ensures you'll receive extra attention and necessary modifications from the instructor. After all, proper form is key to seeing results and warding off potential injury.