My guide to successful bidding:

Watch an item rather than bid immediatly, and leave your max bid at the last possible moment

When placing a bid place an unusual amount for example if you were going to bid £10, instead bid £10.01,£10.02 etc, as most bidders tend to bid an amount that is rounded it may just get you the item for a few pence more.

Sellers may charge extra for postage, packing,paypal etc, so always read the auction carefully, so you know what your total amount will be.

Check out other items that have been placed in the wrong catagories, for example a pair of  designer shoes that may have been listed in the ladies tops. So check out all catagories when looking for an item and not just the one it should have been placed in.

Time of year: As a seller I know that some times of year are quieter than others for example after christmas and peak holiday times (people tend to be skint , so it may be worth waiting a few weeks for that must have item !)

Hope this has been of help to ebayers and budding ebayers.

Good luck with all your bids !