Every time I sit down to write a new scene, I have a series of questions I ask myself:
What is the worst outside thing that could happen? Could physical harm befall the character? Could there a a confrontation with another character?
What's the worst inside thing that could happen? What could make it more emotionally wrenching? What fears does the character have? Could the character's career be at risk? Could someone the character cares about be in trouble?
What's the coolest thing that could happen? What's the coolest/most interesting setting where this scene could take place?
What new - and awful - information can be revealed?
How can I make what's happening bigger and more important? How can I raise the stakes?