I was trying to make my opening paragraphs sparkle for my new book. The last two novels I have spent ages agonising on what I wrote when it dawned on me that I don't really need to do that.
Once you have written your novel, you can pick out some of the main parts from the whole book and begin your opening lines, based on the main story, without giving too much away.
I have started with a couple of paragraphs about my main character and done a teeny bit of foreshadowing from later on in the book. Now, if I hadn't finished writing the story as a first draft, I couldn't have done this and would have kept on agonising over what I was going to write. As a result, I have something very sparkly and positive and keeping the reader reading knowing what I now know. I think that works.
The point I am making is that, don't worry about writing the opening lines, because later on your story will guide you. You can always go back and write it for real when you know how the story is going to continue. You will have more information by then and be able to write your opening lines with confidence because you then know how it's all going to end.
I hope this is helpful for the 'newbies'. I have re-written my opening lines so many times and changed them, but the best openings came from further on in the story.
Lin