Quick Tip: Plotting Plots
The bare bones version is this: when you plot your plot, write down in order of appearance all of the major twists and turns of your story. Make note of huge revelations, the conflicts, the unexpected events that happen to your main character and what he/she does about it. Get it all on paper, to the best of your ability, exactly what it is that happens in your story and then look for problems. Search for holes in your plot as well as gaps of time in your story where you notice nothing really is happening between page 50 and page 100. Let this be your guide for adding more bulk or removing excess from your story.