Should my query be long or short?
I say err on the side of brevity. That is to say, some agents might not mind long queries but others (myself included) prefer shorter ones. So you don’t turn anyone off, your best bet is to go with something on the shorter side, whilst keeping it catchy and terrific. I’ve blogged extensively on what to include/not include and how to structure a query letter. I can revisit that another day, too.
What’s the scoop regarding comp titles?
If you’re going to use comp titles, choose wisely. For example, perhaps you don’t want to say you’ve written the next Harry Potter or Hunger Games or The Fault in Our Stars. A comp title should be used so that the person reading the query gets a sense of what your story’s about. So, if you said, “My story is like Game of Thrones with a cast of rats,” I’d totally get what you were going for (and I’d definitely pass on that… sheesh!). Or if you said, “My story has the feel of Miss Peregrine’s Home for Peculiar Children, only set in New Orleans right after Hurricane Katrina,” it would also be clear. So if you’re going to use comp titles (and it’s not required), make the comps work to explain your manuscript, don’t compare your work to another author’s (especially a blockbuster author’s).
How much should you suck up to the agent?
Don’t suck up. If you’ve met the agent, you can mention it, if you want. If you really adore some of their client’s work, you can tell them. But making stuff up because you’re supposed to try to “connect” usually comes across as inauthentic, in my opinion. It’s nice to know when a blog follower queries me, because I can thank them for following. But it doesn’t earn them “points” or something; I don’t read their queries any differently. So yeah, don’t suck up.
What else do you want to know about queries?
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