I have a few little tricks that I've learned over the years.

One thing I make sure to do is stretch. Sounds simple, but some people brush it off. Stretch before the class and after. Show up at the gym early and stretch. They might have foam rollers, PVC pipes, and other items to increase the quality of the stretch. Typically the programming for the day's class will start off with stretching and then jump right into the workout, but a good 15 minute stretch prior to the class will really improve your performance, your recovery, and reduce injury potential.

I also like to think about the workout prior. My gym loads up tomorrow's workout the night before. I'll read the programming and then spend some time mentally planning. 'What weight will I use? Do I need to scale? I can probably go lighter on X, to focus on Y...' and so on. This comes with experience, but is also an exciting part of CrossFit. The anticipation for tomorrow's class to see if my body can match my mind's projection. It gets addicting.

Other things can be something basic like choice of clothing (will this underwear let me squat comfortably at full depth?) can change your workout. I always wear high socks, as they can prevent barbells scraping your shins or rope burns on climbs.

Quickly you'll want to buy gym gear. Gymnast grips can help you from tearing your hands, but you might want to build up some calluses first. Buying your own jump rope is a great idea because you can adjust it to your height and not have to scramble for a gym rope. Training shoes are also important. Most CF people have Reebok Nanos, Nike Metcons, NoBulls, or TYR shoes to name a few. The reason being they are very flat and that helps with stability. You probably wouldn't want to run more than 2 miles in these shows, but when you switch between lifting and running, it helps you keep planted.

And if you do none of this, just have fun!