关于止损政策的问题 (Question about stop loss policy)

I am sure, like me, many traders do not like to see a trade go against them when they enter it. I look at longer and shorter time frames (usually) to confirm that the trade I am planning will be a good one. Inevitably there are those trades which seem to go wrong and the worst ones are when the price seems to accelerate in the wrong direction!

I'm wondering if anyone can impart some knowledge about stop losses and how to manage them at the beginning of a trade. Is it a good idea to set it small initially and then increase to a realistic amount as the trade matures?