What qualifies as a larger-than-life action? Winking at a stranger is easy for a flirt; to a shy person it is huge. Taking a swing at someone is no big deal for a boxer; but for a timid person it is life changing. Whatever it is, it is a surprise. It should feel big. It feel outrageous. It is satisfying because once in a while we would all like to let loose our inner devil or angle. So here is your chance. Let you character do, say or think something memorable. A larger-than-life character is one who says, does, and thinks things that we would like to but never dare. Push your characters out of their own bounds, whatever those might be.
Donald Maass gives a writing exercise to help us in creating these larger-than-life qualities in our protagonist in his Writing the Breakout Novel Workbook. I bought it as a gift to myself for the holidays. I would recommend it buying it and using it during the revision process.
Step 1: Write down the following:
What is the one thing that your protagonist would never, ever say?
What is the one thing that your protagonist would never, ever do?
What is the obe thing that your protagonist would never ever think?
Step 2: Find places in your story in which your protagonist must say, do, and think those very things. What are the circustances? What are the consequences?
Look through your manuscript for places where you paotagonist can break through his boundaries.
Find a single point in the story in which your protagonist pointedly lets go of an opportunity for a larger-than-life gesture.
Hope you can find the time to give this exercise a try.