I use different strategies depending upon what the item is.
For example If I find something worth around £100 to me and there are no bids on it, I will put a bid of something like £60 - £70 on it to hopefully show others that I am keen and then come back near the end with 2 tabs/pages open and then bid up to £100 - £110. I try not to get carried away with auction fever.

If it is a common/plentiful item I’ll just put a bid on and wait until I get an e-mail on my BlackBerry to say if I have won or not. I have never tried sniping tools.

A few years ago I was trying to get a tube of molycoate grease for my Dad (to use on his airguns)..... there was a seller who had about 20 tubes for sale... I was out-bid by the same guy on the first 2 or 3 tubes until I realised that his max bid was always the same (£10)..... I out-bid him on the next tube and then proceeded to place a bid of £9.99 every time he bid on a tube... I made him pay for pi**ing me off.