For the most part, filling out a proof of loss form is straightforward. Since your insurance provider will give you a form, you need only provide the information it asks for.
As mentioned, that will include information about the loss, such as the date and time, and your description of what happened. You'll need to list the damaged or stolen property as well. You'll normally also need to fill in some basic information about the associated insurance policy and the parties it covers.
The most important thing to remember when filling out a proof of loss form is to be as accurate and thorough as possible. Remember, your eventual claim settlement will be based on the information you provide on the proof of loss. You don’t want to shortchange yourself, but you also don't want to misrepresent anything in an attempt to claim more than you've lost; this is insurance fraud, and it can result in the entire claim being denied outright. Serious cases of insurance fraud can even result in up to 14 years in jail.
Basically, the supporting evidence you provide should reflect the actual loss you're claiming.