Exactly! This is called sharpshooting. You DO NOT bid on the item, this will only drive up the price and alert other bidders that there is another contender.
I do not bid more than once. I bid only once in the last 15 seconds. Determine what you are willing to pay ahead of time.
Put it in your watched items list, note the time it will end. With a half hour to spare, log in with a cup of coffee and get ready to enjoy the fun. The faster your internet connection, the better.
DO NOT bid until the last 5 minutes. Be prepared to bid several times in a row as the last bidder may have set a higher bid than what shows. If others are sharpshooting (likely if it is a hot item) get ready to volley back with your bid, but know what you max bid is, lest you pay more than you intended.
Know when to let go.
This is most important. Set your own price. What am I willing to pay for that item? You do NOT have to beat the other bidders. If you lose this one for the price you are willing to pay, there will be another just like it next week. I got a GREAT 6 CD carosel type changer for under $10, plus shipping. But if you get caught up in a bidding war trying to beat the other bidder, you will just pay too much. You are working against your own best interest. Like a gambler trying to win back all the money he has lost on that one big bet.
I open the page in two windows. One have have signed in, clicked the Bid button, entered my bid amount. The other I refresh about once a minute during the last 10 minutes, and when it gets down to 2 minutes, I just keep refreshing, watching the price. If it goes over what I am willing to pay, I quit right there. If not, with 10 seconds to go, I bid.
I do pretty well, too.