One rule to rearranging is making sure it makes sense with your space, and the furniture balances out the space as well. The space above would completely changed if there were't doors on each side. But with this set up, the furniture is the focal point, and very symmetrical.
This format gives you more freedom. Mixing and matching furniture pieces and feeling cozy. But make sure to make an opening so people go in and out of the space. This kind of space is the kind where you can throw in an ottoman or pouf. This space is all about flexibility!
Most basic set up is to place the sofa directly across the main focal point, This set up is practical to many, but when having a larger group around, it's a great idea to have ottomans around to make more a natural circular gathering. The picture above is a great example because they have a ottoman/coffee table they can move around.
Hope you're inspired! Let the furniture moving begin!