Do not overtrain. The best muscle development happens gradually. If you force it, then you will only grind your body into injury and fatigue. Provide enough stimulation to improve but know when to stop. Hours and hours of aimless exercise will achieve nothing. Follow a sensible program.
Schedule rest and recovery. Fitness is not just achieved through hardcore exercise. You will also need to rest and recover so that your body has enough space to repair micro tears and grow the muscles to adapt to the stress. If you don’t schedule rest, then you will get injured and will be forced to rest.
Be careful. You need to exercise caution when using the plyo boxes Crossfit, especially when jumping up or down. Do not hurry. Don’t take on more than you can handle. Land with your knees bent to cushion the impact.