There are a few things you can do:
Always make sure you wash your hands before touching any unpackaged food
Wash your fruit and veg before you use them
Separate raw and ready-to-eat foods when you store them in the fridge
Keep your dry food separated from any liquids
Always use clean utensils when cooking
Also, look out for fridge freezers with hygiene tech which keeps bacteria away from your fridge, so your food stays safe and hygienic for longer.