Since I’m still struggling with my current draft, I’d like to suggest a couple of links about beginnings. What got me thinking about this was a quote from Gabriel García Márquez on how the first paragraph contains the whole book:
One of the most difficult things is the first paragraph. I have spent many months on a first paragraph and once I get it, the rest just comes out very easily. In the first paragraph you solve most of the problems with your book. The theme is defined, the style, the tone. At least in my case, the first paragraph is a kind of sample of what the rest of the book is going to be.
Talk about setting the bar high! This is why I don’t understand how you can write a good first paragraph until you’ve written the rest of the story. Or at least, maybe that’s how it works for me. He seems to be saying he works out a thorough sense of what the whole story is going to be while he’s wrestling with that paragraph.
And how do you know you have a good opening? Well, in this excellent discussion from Shimmer Magazine, a brave-hearted slush reader breaks down exactly the who, what, and why that can make a reader care about your story. By the way, where and when won’t do the trick so much unless you can write in beautiful language.
After reading all those slushy examples of how to get it wrong, the example that leaps to mind of a beginning that gets it right is “Special Economics“. In one paragraph, you receive an immediate sense of what sort of person our heroine is, the nature of her surroundings, and what she wants.
Hope that gets you started.
Writing Every Day 
I’m going to be a curmudgeon and respond by saying that one person’s grand opening is another person’s, I’m bored, next story. I went back to read the opening and was immediately confused by “plague trash market” since the phrase was cumbersome to me, altho I figured what it meant more or less. The slush guy has his desires, but I read stories all the time that accomplish none of those things, yet are published. Yes, est. writers get a lot of slack to do what they want, but then how are new writers supposed to know what’s acceptable? Anyway, I always like your beginnings, Pam 🙂
You’re right to point out that what makes an effective opening is also a matter of taste. What the slush reader is doing is pointing out what exactly they are reading for in an incredibly helpful and specific manner. I do try to do a lot of the things they ask for, so if you like my beginnings, maybe I’m doing something right.
Thanks!