This seemingly counter-intuitive advice was given to me by my new editor. When you think about it, it makes sense.
What grips the reader from the start? It's not a slow build or descriptions of people and places. It's action, tension, drama. Of course there needs to be a reason to care, otherwise no amount of action will keep the reader interested. In fact, too much action too soon can leave the reader quickly feeling jaded. After all, if you threaten your protagonist with death in the first chapter, the reader will know you're not going to kill them off so soon, so they'll just want the action to end so the real story can begin.
So what do you do? Keep it simple. Kick things off in the middle of something important to your protagonist, but which can be brought to some form of resolution soon enough that the reader can be brought up to speed shortly. Ease the reader into the story from there, feeding them little bits at a time instead of either cramming it all down their throat at once or starving them for excitement by dragging things out.
Threaten the protagonist's values or goals, rather than the protagonist themselves. Give them an early setback to set up the later story. If the tension at the climax is a 10, open the book on a 4 and let it drop to 2 or 3 after the first chapter. That's when you can introduce the finer details of the setting and the goings-on of your world.
I had to learn this the hard way. When I first started editing Locked Within, the first 50 pages had to be cut because I started the story too soon, with not enough tension to keep the reader interested. It was that long before the real story began. I've made sure to correct this in anything I've written since, to make sure I don't have to lose editing time to that kind of work again.
For the writers, how do you like to start your stories?
For the readers, what are some of the bets openings you've read?
Don't forget my Hero's Journey Challenge. Suggest me a movie, and I'll see if I can apply the Hero's Journey model to it in a blog post.