Dixon says, "Make your first paragraph carry some weight."
One of the most helpful things I’ve learned from my critique group is to start each chapter with a paragraph that makes it clear (1) where the action takes place, (2) which characters are present, and (3) which one is the POV character.
For those who use omniscient POV, this last aspect may not seem so vital. As a reader, however, I sometimes feel cast adrift if I can’t answer this question pretty quickly – “Whose story is this?” I remember reading a paragraph from a Tom Clancy novel. It starts in the mind of a Secret Service agent, jumps to some thoughts by the President, takes another jump to the mind of a wannabe assassin, and ends up back in the head of the Secret Service guy. Clancy is a great storyteller but maybe a bit undisciplined. (I should be nice, though, since he’s never said an unkind word about me. Fact is, he’s never heard of me.)
I originally wrote a scene for MONTANA IS BURNING where Paul Longo, my detective protagonist, and another man are having a conversation in a sparsely decorated room. Halfway through the scene, the reader learns Paul is confessing to a Catholic priest. Trouble is, nobody who read the scene enjoyed it. They all felt I was being sneaky. Yeah, they were right. As a literary agent told me at the first writers conference I ever attended, “Dixon, don’t be so damned subtle. Sometimes you just need to come right out and say what’s what.”
So I have come to believe that suspense comes from a well-plotted story, not hiding the facts from my readers. (They both get cranky if they can’t figure out what’s going on.) One last point - when writing your opening, keep in mind you’ve got a whole paragraph to work with. There’s no need to cram everything into that first sentence.