So when I ask the question “If at first you can’t succeed, how about changing direction?” it means simply this: look deep into the characters you developed. It all starts there, not with the plot or the setting, but with the characters. Sure if you are writing a thriller, you will have a hero and villain. If writing a mystery, you will have the detective (in many forms, from a florist to a real cop) and some sort of crime where everyone could do it and had the chance to do the crime. But the real important part is building up your characters from the beginning. You don’t have to spend a lot of time talking about what they are wearing, or how tall they are and their hair color. Frankly, who really gives a damn? That has 100% absolutely nothing to do with who they are as a person, so take the image out of the equation. What do you have left then? You have how they react in certain situations, how they become a ruthless bastard, how they obtain the skills they have, what gets under their skin, what makes them want to continue forward… I could go on and on, but I think you get the idea. Talking about what they look like with height, weight, hair color, shirt color, do they have a piercing, all that stuff is simply fluff that can be explained in other ways and a lot more interesting. This goes for ALL your characters in your book, not just your main character.
Secondary characters are just as important, if not more important than the couple of main characters you have in your book. What they do is put the ribbon on the package, or the tape on the wrapping, they bring your story together. Without really thinking about secondary characters, you end up with a present under the tree that looks like an open umbrella, not surprising anybody that is going to open that present. Research comes in many different forms, from getting the history of the city right or the curse of the tomb, to bringing your characters to life and how they act and how they got that way.
So when you are writing your story and come to a crossroad where you need to make a decision, ask yourself first if the road you traveled to get to this point has been successful, or do you need to double back and take a different road. Weaving through the maze of words that make up a book is something not to be taken lightly. Stop being stubborn and realize that maybe your book is simply crappy and be honest with yourself, it is then and only then, you become a writer that readers will be happy to support.