1) Check out your seller's feedback thoroughly before you bid! Are there a disproportionate amount of "not a registered users" in their feedback profile? Is there a disproportionate amount of "0" and "1" feedback users in their feedback profile, with suspicious dates? For instance, make sure feedback is being exchanged only a few hours after the auctions close.

2) Check out the bidding history of your seller. Are they placing bids exclusively on another seller's items? If they are shilling for another user ID, the chances are someone is shilling for them as well!

3) Check the bid histories of ALL the bidders on the auction. Simply view the "bid history" of the auction in question, and plug those names into the bidder search engine. Are any of the bidders bidding exclusively on your seller's auctions? This is perhaps the most important step to avoid shill bidding--always check the bid histories of any auction before you bid!

4) Snipe your bids! The closer to the end of the auction that you place your bid, the less likely you are to be SHILLED. For instance, placing your bid 10 seconds before the auction closes would practically ensure you wouldn't be shilled AFTER placing your bid, as there isn't enough time. This doesn't guarantee that the auction hasn't already been shilled up to that point, but it does prevent it from being shilled further AFTER you bid.
Article submitted by bearalltosee