hogwartsishome | Newly sorted, with a question

I've just gotten sorted over at Platform_934, and I'm wondering by what criteria people are sorted.

I think I'm pretty clear on the defining characteristics of Gryffindor, Ravenclaw, and Slytherin (bravery/chivalry, intellectualism, and cunning, respectively), but I'm not sure about Hufflepuff. I've read all of the HP books so far, and more than my fair share of fanfic, but it seems to me that there are more subtle reasons that the hat places characters in various houses. How do you choose who to sort into which house? I'd welcome your more detailed critera for sorting for any house- I want to do it right!

Thanks!

Terrierhead, Brand New Gryff'