I often hear actors debate the question of whether to sit or to stand in an Audition. As a coach, my answer is to them is often "What will you do when you get to set? Do that." 

When we get away from the mindset of auditioning, & get into the mindset of creating a scene, we'll no longer ask that question of ourselves.

I recently attended an Agency Showcase in a hotel conference room where actors from various markets presented a scene to the agencies. Imagine a hotel conference room.. the lighting isn't great, the walls are sorta bland, the room is big. 

I noticed that the actors who chose to stand & create a scene that had a real beginning, middle, & end were exceedingly more captivating than the actors who chose to sit. In this case, the space played a major part in the end result. 

So keep the idea of "playing the space" in mind if you're still wrestling with whether to sit or to stand in your audition work. You may also err on the side of "which...