Not everyone may choose to have their pet cremated, and in those instances, pet burial might be for you.
If you want to bury your pet at home, it's important to check your local laws and regulations to make sure it's allowed. Try to select a spot that likely won't be disturbed, (call before you dig, to check for underground utility lines) and consider marking the area with a special plant or a personalized headstone.
For environmental reasons, be sure to only bury your pet in biodegradable materials like wood or cardboard.
Here's an article from the UK that talks about precautions and steps to take.
Pet Cemeteries
If a home burial is not possible or preferred, there may be companies in your town that offer pet burial services. Talk to your veterinarian about options they might recommend, or look online for "pet cemetery."
Your city may have a dedicated pet cemetery, some pet cremation businesses may provide this service, or animal rescue shelters, or perhaps even some churches.