Having just dug myself out of a small pile of contest entries (2 contests that happened to overlap, bad planning on my part), I come with a new appreciation for slush pile readers. Reading slush is not like reading a book you bought at a store that has a description and a cover blurb. I know these (as all stories do) represents someone's blood, sweat and tears. I also know that things that work or don't work for me, will elicit different reactions from others. And, as is often said in the review business, there are quite a few things that just make you think, meh. But here are some things I discovered put me in a not favorable frame of mind towards an entry.
1. Clip art. There should not be clip art or graphics or cute drawings in your manuscript or synopsis. If you have something that you stuck in there to inspire you while you were writing, take it out before you submit it.
2. Unorthodox capitalization. You may be writing Contemporary, or fantasy, or Something Else entirely, but this does not Give you license to invent New capitalization rules.
3. Pointless scenes. I am a terrible violator of this rule, so, much like that dieting friend who's always counting your calories for you, I am easily irked by this. Here's the thing, if the scene is really fun, most readers will let it slide, but early on* if the first three scenes only teach me the same two things about the main characters, well, this is me getting bored.
4. Overuse descriptions. Now this is one that I am terrible about doing, but I think people tend to fall into a writery sense. I think your average person does not meet someone and think, "Wow, their eyes look like the sea after a summer storm." I think people go, "Huh, gray eyes" or possibly even, "Nice gray eyes." Now sure, there are people who think in more artisic terms, and if your character is one of those people, I am fine with that, but I read a lot of entries where people looking at other characters suddenly turned into some sort of poet.
5. Excessive cliche use. Look cliches are a great shorthand and can be very useful, but there is a limit. Just like you can't overuse a pet word (or six) don't have everything be a cliche, unless of course, there is some character specific reason for them to think in cliches.
6. Have characters say things that constantly have to be explained. I have read entries where someone would say something and then the thought following it would explain what it really meant. Again, there are times when this is necessary, but if it happens too often, then I start to wonder why your characters never say things that just make sense.
7. An insane synopsis. Now insane is in the eye of the beholder, but I read a few entries where the pages I had were good (not great, but good) and I flipped to the synopsis and it turns out what seemed like a nice little cozy story took eight or nine left turns and landed us in the city of ridiculous coincidences.
*These entries were mostly the first 30-50 pages.