Everyone has their own way of bidding, their favorite method that never fails and always works. Basically the strategies are broken down into 5 different areas. Bidding early , Bidding Aggressive, Bidding with a proxy, Bidding Late (Snipping) and not Bidding at all.

Bidding Early
This is a bidder that is looking for a good deal. They place a really low bid with the hopes that they will score a really good deal at the end of the auction. They don't really care if they win or not and are probably not going to pay much attention to auction after they place their maximum bid. Basically they just place the bid then wait for eBay to notify them if they were lucky enough to win. Sellers encourage this kind of bidding, it gets the ball rolling. Active auctions get more attention then stale ones.

Aggressive Bidder
This bidder doesn't like to lose. They watch their auctions like a hawk and will counter a higher bid almost instantly. They like to intimidate other bidders, especially new buyers. They slam a higher bid down to show they mean business and are willing to put up a good fight to win. They want to show you that they are going to outbid you no matter what so you might as well give up sooner then later because they will not give an inch. Essentially they are just using "scare" tactics to ward of potential competition. It's a more confrontational approach (though not unfriendly), but after being outbid a couple of times, other bidders usually decide their efforts are futile, so this approach does work.

Proxy Bidding
This is the bidding approach eBay recommends. This buyer does a little research before hand and figures out what the item is worth and how much they are willing to pay. Then they place their bid and let the program do the rest. They know that there is no danger of going over budget on an item and if no one else bids on the auction they're going to get a good deal. This bidder can place their bid early and walk away knowing that the software will counter-bid to regain their high bidder status until the max bid is reached. This is a great strategy to use for every day bidding, as it's the safest most efficient way to win a lot of auctions and not go over budget.

Bidding Late (Snipping)
This bidder likes to catch their competition off guard by coming into the auction and placing their bid at the last possible moment. Their goal is to place their bid and not give the competition time to counter. The last-second bid can often get you a decent price without leaving opportunity for others to challenge. Make sure your maximum bid is hefty enough to thwart the current high bidder or you'll succeed only in gaining a last-second "you have been outbid" message. This method is very effective but comes with risk. If you wait too long to bid, the auction could close before your bid is processed. If your maximum doesn't beat the current high bidder, you won't have a second chance to up the ante. And don't overlook the fact that you could be in the company of other snipers who are ready to snipe your snipe.

Not Bidding
Knowing when Not to bid can be as challenging as when to bid. It's so easy to get caught up in the "whole auction thing" and starting throwing bids left and right just so you can win. Over bidding yourself is no fun, even if you didn't mean to spend that much you are obligated to pay the seller. They don't want to hear excuses as to why you went over budget. You also don't want to get caught in a bidding war between two people. This is not a good place to be in, if they are bidding against each other they are just going to stomp your bid without even noticing. You don't want to be the last one standing if this occurs because you will pay a lot more then you should for an item. Remember, most items will appear again on eBay so all is not lost if you are out bid. Discipline yourself not to bid on the first item you see. Auctions usually run for several days, so take advantage of that and shop around. You might find the same item in better condition, or you might find an entirely different item you'd much rather own. Being choosy is good when you deal with online auctions.