I recently discovered the September C Fawkes blog; I have only read a couple of articles but this is one blog I have bookmarked and will re-visit many times. The post I found first is this one: Ask September: How do I come up with a Good First Sentence? Here September talks about first lines and has a list of poor starts to stories.
The list of bad openers is an eye opener; I found four ideas for piece / books / shorts all on this list and all need a re-think. Do let me know if your experience is similar!