Bearing in mind that I tend to work for small to medium private companies that ask for a CV and cover letter - I don't really apply for things like charities or public sector where they have more structured application forms, which is a very different world.
What are some of the little details that would make you accept or reject someone's application? I'm not talking about the big things like that the CV was full of spelling errors, or that the person was very obviously not suitable for the job. I'm talking about some little nuances, things along the lines of "I would've invited this person for an interview if it wasn't for this minor little thing that somehow put me off".