Tips for writers, 1: Introducing your characters

Starting a story? Start it with your hero. One reason Edward Bulwer-Lytton's famous opening

It was a dark and stormy night; the rain fell in torrents, except at occasional intervals, when it was checked by a violent gust of wind which swept up the streets (for it is in London that our scene lies), rattling along the house-tops, and fiercely agitating the scanty flame of the lamps that struggled against the darkness.

is so famously bad is that there's no one there. Lots going on, but where's our hero? We meet him soon:
Through one of the obscurest quarters of London, and among haunts little loved by the gentlemen of the police, a man, evidently of the lowest orders, was wending his solitary way. He stopped twice or thrice at different shops and houses of a description correspondent with the appearance of the _quartier_ in which they were situated, and tended inquiry for some article or another which did not seem easily to be met with. All the answers he received were couched in the negative...
but don't really get to know Mr C until he takes action:
He was admitted by a lady of a certain age, and endowed with a comely rotundity of face and person.
"Hast got it, Dummie?" said she, quickly, as she closed the door on the guest.
"Noa, noa! not exactly; but I thinks as 'ow--"
"Pish, you fool!" cried the woman, interrupting him peevishly. "Vy, it is no use desaving me. You knows you has only stepped from my boosing-ken to another, and you has not been arter the book at all.  So there's the poor cretur a, raving and a dying, and you--"

But enough - you can read Paul Clifford by Bulwer-Lytton on archive.org, should you wish. 

For an opening to be good, your reader has to sit inside the head of your hero and look through his eyes. Or her eyes. Looky here:

Many years later, as he faced the firing squad, Colonel Aureliano Buendía was to remember that distant afternoon when his father took him to discover ice.

See what Gabriel Garcia Marquez did there? You want to know immediately what's going to happen to the colonel in One Hundred Years of Solitude. And look at James Stephens' opening to my favourite dog story of all time:
There are people who do not like dogs a bit--they are usually women--but in this story there is a man who did not like dogs. In fact, he hated them. When he saw one he used to go black in the face, and he threw rocks at it until it got out of sight. But the Power that protects all creatures had put a squint into this man's eye, so that he always threw crooked.

Stephens' readers immediately sit down and settle in for the story. Even the dog-lovers do. Especially the dog-lovers, in fact, since they're the ones who have a stake in the fate of the dog we know is definitely going to walk into the story. The fact that the dog is an aunt of Finn Mac Cumhaill's will make the story all the more interesting - but that's for later. 

So when you're starting your story, start it with your hero, and make sure he's about to face a challenge that will define him and make your readers root for him, or hate him, but anyway make them absolutely want to know what's he's about to do.