Last week at the library book sale I picked up The Art of Dramatic Wr!t!ng (sic) by Lajos Egri, first published in 1946. My book was published in 1946. My edition was published in1960, and it must have been kept in a box on someone's shelf, because it's in mint condition.
And that's too bad, because it's a terrific book that should be read by everyone who wants to write anything. It describes crafting the premise of your story and how to develop your characters. I'm only on page 50, but I've realized that my hero's motivation is deeper than I suspected. I'm going to have to add that.
If I hit a bump in the story, my usual solution is to add more conflict: if he got hit by a bus in the last chapter, she's gonna get hit by a train in this one! But conflict doesn't have to hit them from the outside--sometimes the trouble comes from the baggage we all carry with us. And, sometimes, that's more difficult (and painful) to deal with than a speeding train.