You know, I’ve never had any luck with that. Usually that’s a spiral straight down into feeling like I have never and will never write anything worth anything.
And yet, so many people promote it as THE solution to breaking through writers block. Go figure.
My solution so far is to brainstorm. Where can the characters go from here. What are the possible consequences. What action will bring the plot forward. What action will cause them the most trouble with its consequences. I usually manage to find a path for them amid the dozens of ideas I look at, and that is my path through the writers block. Preferably it is a path that involves both advancing the plot and getting the characters in the most trouble possible via an action that they thought was reasonable at the time.
Fortunately NaNoWriMo has helped me realize that my story doesn’t have to be perfect, only that interesting things must happen, and the most interesting things usually involve the biggest problems for the protagonist!