I took pics of the serial #s for all the TVs and PS4 and everything else now. I had Allstate and Farmers when the break ins happened. I hadn't had policies for long, so I got back way more than I put in. And keep lots of pics.
This.
I work in insurance, so I can attest that you should take pics of the things you own and the labels with serials and everything if at all possible. Also a good idea to take pics of the items in your place as they are day to day. Put them in cloud storage with whoever you use, apple, google or whatever. If you bought anything on credit or debit, pull the records. If you buy cash, consider taking pics of your receipts if you don't keep them and storing them remotely as well.
As far as cash goes, most insurance companies have a cash limit for the basic reason that cash on hand in your home cannot be verified and fraud is a serious business. There are people that buy receipts from websites to claim items fraudulently, so keep in mind that it's best to have various forms of documentation.
Jewelry has limits most of the time as well, so if you have anything of decent value you should consult your insurer about getting separate coverage for each of those items.
And make sure you are cool with shelling out your deductible, if you aren't you should really opt to pay a higher premium. Otherwise, when your deductible eats up most of what you are claiming you really have nobody to blame but yourself.
Lastly, understand that the insurance company expects you to replace the items you are claiming. If you report it and they accept it, they might only give you the actual cash value of the item and hold on to the remainder until you replace it and submit documentation to release the rest of the money for replacement.
Sorry to hear you got taken OP, hopefully it all gets squared away.