"There are two kinds of beginnings in fiction: the sentence that gets you started and the true opening sentence, which may not find you till you are well into the work. "
I love the notion that your work finds you. The opening sentence and main character of A Closer Look found me after I'd written 80 pages of a middle grade novel about girls who would donate their hair. I plotted that the main character of the MG novel would come upon a girl sitting on the beach having a quiet discussion with her mother. The girl was awaiting her first prosthetic wig. She was wearing a hat and was constantly adjusting it, obviously worried that it would fly away in the sea breeze and expose her bald scalp. And that's when it struck me that the girl on the beach, Cassie's story was the one I needed to tell. So I scrapped those 80 pages, started researching and started all over again.
So patient with your stories and characters because they may be the guides who lead you to the opening sentence of the real story you are destined to write.
The opening sentence to A Closer Look:
"It was New Year's Eve, but I didn't care how I looked--jeans and a sweatshirt, hair in a ponytail--done deal."