Well, we can be honest here - there are a few camps out there of what to do when faced with a prologue. There are the diehard skippers who never look back. There are the ones that always read them, and then there are those who will go back and read it later if the text is intriguing enough to warrant it. I'm definitely in the skip it and go back later camp, but it also depends on the length of the prologue and what it seems I'm going to have to sit through.
If it's really long and it's something that happened a long time ago in a galaxy far, far away and is foreshadowing of foreshadowing, then that's a problem. If I had to caution a new writer on their prologue, I would say, try your story without it and just jump right in. However, as a writer who wants to play with all the toys myself, I would caution a fellow writer to consider the structure of the tale they want to tell, i.e. is the prologue a twenty-page info dump? Is it written in another style? Is it involving a host of people that haven't anything to do with the current cast of characters? Well, that could be a problem. I don't blame a new writer for wanting to flex all their muscles, but if you want that prologue to be read by most, then keep it short, keep it punchy and make sure that it's memorable enough that when something does loop back to it, the reader goes, AHA! and not, What the heck was that about?
In the original draft, my prologue started with, My name is Albert and I was nine-years-old when I died... and that's a pretty solid opening line. The biggest issue the 1st readers had reading that version was that Albert was set up here and then never referred to again. Of course, as a writer, I'm going, 'but it's all part of the big picture that you'll see over time! No, really!' And lot of other blah blah blah. It was all the same things that make me say, SKIP! when faced with such a prologue as a reader: lengthy, with characters that are not in the rest of the book, (or at least on the book jacket). The length of that first draft was too long for the publisher to commit to, and that forced me to restructure the book into 2 parts. I had to take a hard look at how the beginning bridged to the middle and then bridged to an all-new ending point.
I took a passage from the new Bully Part 2 and placed it at the front of Part 1 as a prologue. Son, I'm gonna hit you... is also a great opening line. It is a clear foreshadowing of actions involving the main character and the darkness he faces - both of which are clearly on the book jacket itself. It's short. It's punchy, (literally). Albert moves to the first chapter, and, having the option now to restructure the work, I took images and ideas from Albert's chapter and repeated them throughout so that even if Albert himself doesn't reappear, you can feel his ghost throughout. To reinforce Albert, he appears in a short and punchy prologue to Part 2, and following that, another appearance in Part 3, and by Part 4 he takes the stage as a major character.
I'm still not sure the Albert chapter fully works, but once the entire series is read, it all makes sense - blah blah blah. It's been a long time getting to this point, and having the book actually see print, so I'm going to flex my creative muscles and write prologues and vaguely dramatic foreshadowing - though there is one thing I won't do - an epilogue - that's surely the mark of an amateur! HA!