Final answer:
Regular handwashing is the best method to prevent cross-contamination.
Step-by-step explanation:
The best preparation method to prevent cross-contamination is regular handwashing. Washing hands before and after handling or preparing food, after using the bathroom, and after being around sick people helps to remove potential pathogens that can cause contamination. It is also important to properly clean and sanitize utensils, countertops, and cutting boards after handling raw foods that may contain bacteria.