validating by linking any of the following: facebook, phone, credit card, or bank account. also if you write your user name on a piece of paper and put it with the game then take a picture and post it, it helps confirm that you actually have the item. also don't forget to include information about the item, like does it work properly? since its a game does it save? if you list clothing items be sure to let people know if the item comes from a smoke/pet free home. and if you require the auction winner to pay for shipping let bidders know how you accept the payment the safest way being paypal. also be sure to only ship to listia verified addresses as per their rules.