Having been through the whole small claims court drama to get a deposit back, I can attest to the importance of lots of pictures/video. Also, keep track of ALL receipts for repairs/maintenance, etc. Get everything in writing, and document every phone call, etc.
What we do now is video & photo BEFORE we move in, and video & photo of the same stuff after we’ve moved out. That way, you can show what was pre-existing (good and bad, as many tenants actually improve the property, like you did). Use a picture/video of that day’s newspaper to show the date (as mentioned above).