You can still make your query letter sound professional AND make it stand out. Like someone else mentioned, making it stand out doesn't mean cliche tricks that literary agents have seen a thousand times before. the thing you need to remember though, is to make sure what's unique about your novel comes across in your query. That's could make the difference between them asking for pages or sending a rejection, especially if it's in a flooded market like YA dystopian.
You can't please every literary agent. The reason you see so much conflicting advice is becasue there's no one true way to write a query letter. The best query letters are those that entice the agent to want to read more. YOu do this by being specific and not vague. For example, instead of saying, your character has to battle monsters throughout the novel, give an example of what she has to face. What I've learned about queries is that you have to be specific because when you're vague your book will sound generic and literary agents aren't looking for the next generic knock-off.
When you start reading real query letters, one thing you'll notice is that they're all different. Each query letter is not written in a specific format. But, they all do one single thing: entice the agent to want to read more. My favorite example is the query letter for The Demon's Lexicon. It goes against everything you might have learned about how to write a query, but it did what it's supposed to do - entice the agent into reading pages. that's all you need to do. And that's much harder than I'm making it seem. I can also point you to successful query letters that are outside the box, like the query letter written in first person from the character's perspective. It can be done (query shark even has an example or two on her website that were successful), but you have to make it work and not have it read like a cheap trick.
Writing query letters is hard. What's I've done is read real query letters that have worked. If you run into a writer who has an agent, ask to see their query letter so you can learn from it; some of them post their queries on their websites. Absolutewrite.com/forums has a section devoted to query letters and some of the members have posted their own query letters that helped them score their literary agents. It's also a great place to get feedback on your own query and many writers there are published. The best feedback is on your actual query letter. Reading tips wont' be enough. YOu need to write the query, polish it to the best of your ability and then get feedback from other writers who are also experienced in writing query letters because they'll catch things that you've overlooked or tell you when something doesn't make sense to someone who doesn't know the story inside out.
My favorite place to read successful, real query letters is writer's digest. http://www.writersdigest.com/editor-blogs/guide-to-literary-agents/successful-queries
Good luck with your book!