Put the plot into questions. So, if the purpose of a scene is to get out of the room before the bomb explodes you write "Will they get out of the room in time?" On a more mundane level, if a character is going for a job interview, the question is "Will X get the job?"
Immediately it adds tension. We want the answer to be Yes - but it's more dramatic if No is a likely option. So, all the way through the scene, No must be a plausible - in fact, probable answer. Every time it looks as if X is getting out of the room, or getting the job, something happens that makes it unlikely.
Posing the plot as a question pushes you into making your characters really struggle to get what they want. And as we all know, if it's easy for them, we don't want to read. It's the struggle that makes it all worth while.