1. Not putting "synopsis" somewhere near the top of the page of...the synopsis. I don't ever ask for a synopsis so the fact you sent it in a query letter is stupid in and of itself, but whatthehell, I can get over that.
But, I start reading and it sounds like an FBI briefing, so I thumb through the pages and sure enough...chapter one is three pages into this mess. Do I have to explain why this is first stage nitwittery?
2. Opening with people sleeping, dreaming, watching tv, reading, blogging or otherwise doing static things is the EZPass lane to the "sorry not right for me" Crosspatch Expressway.
3. Opening your query letter by quoting the first page of your manuscript; a page you've enclosed. Why this is stupid should be obvious.
4. Writing "I fixed the six typos you marked on page one so here's my revised query". I marked those because I needed to do one good deed before close of business on Friday NOT cause it was the only reason I said no.
Don't requery unless invited. DO NOT. The way you can tell if I want to hear from you again about this project is: requery when/resubmit/send again after revisions. The way you can tell I want you to hear from you on OTHER things is: keep me in mind for other things. EVERYTHING else is just trying to make you less of a nitwit in your queries to OTHER agents.
5. Pictographs on your query letter- aka inkwells, pens, tablets, open books, or dog forbid, the authoress herself looking pensive --this is a 100% reliable indicator of bad writing. Why? Cause the writer is so busy announcing "I'm a writer" they forget the words are what count.
I don't care if you think it's cute or sweet or your ancient grandmama designed it, take it OFF your business correspondence. There is rampant prejudice against pictographs and you do yourself no favors by thinking we don't notice.
You might say "Miss Snark, you yourself said, 'write well; that's all that counts'" and that is in fact true. I did say that. But when I see those stupid fluffy Rabbitania rejects I expect stupid writing. I was not born thinking this. I have learned this. It's the same reason you do not sit next to the loudmouth at conferences--guilt by association. Don't excoriate me for this appalling prejudice---know it and deal with it.
6. Write your address in felt tip marker on the SASE. Despite all my yapping I do not actually keep a pail of gin on my desk. I do however keep coffee, water, and a vase of flowers. Sometimes those containers fall over--earthquakes; Mr. Clooney sightings; Killer Yapp fleeing the scene of the crime; wayward colleagues trying to steal MJ Rose's ARC of The Reincarnationist; the usual. You address your envelope in green ink and you may never see it again when the address dissolves under a wet paw print either canine, human or agent.
7. International reply coupons. Don't even get me started. Don't waste your time. These require me to go to the post office and stand in line. Not gonna happen. Not now, not ever. Never in fact. Ever. Either buy US stamps or query people who take equeries. I throw these out. I read the queries, and if I want more I email, but if I don't, I don't reply. Save your money. If you're writing from the far side of the moon, just put your damn email address in the query letter rather than include one of these.
8. When you quote an editor from a publishing house that takes unagented work, I know you're quoting a rejection letter. Don't do this. I don't care if the editor said "this is the niftiest novel since Carolyn Keene put Nancy Drew in a roadster with Ned Nickerson tied to the rumble seat". What the editor did not say is "and I'll be making an offer". If I can't figure this out I'm an idiot and why would you want me for your agent?
9. Do not call my office to ask if you can send a query letter. Do not stammer "oh I expected to get voice mail" when I answer at 9pm on Saturday night. Did you think I was going to call you back on Monday? No. I'm not. Neither is any other agent, ever. That doesn't mean you can't query me. You don't need an invitation. Just do it.
10. 8 point single spaced sample pages. Not now, not ever. Never. Discarded unread. No SASE. What a fucking waste of your time and money.