This may sound a bit odd but last minute bidding is very dangerous for me. I'm likely to impulse buy and spend more than I should.
I now use auctionsniper.com and I decide well in advance of the auction closing time exactly how much I'm willing to spend. I enter that amount -- period -- and then schedule a bid time. I don't watch the auction close, if I win, eBay notifies me. If I don't win, I get a note from auctionsniper about being outbid. By figuring out and bidding my max (as it were) in advance and not watching, I curb my impulse buy tendencies and only spend what I can sanely afford to spend. YMMV