Looking through these Basement Framing pictures will give you good design ideas for your own basement.
Here's basic basement framing with a framed staircase.
Here's basement framing with a curved doorway.
Posts can be used instead of walls when framing a basement to get maximum space.
Here's the framing for a hallway and rec room in this basement.
Here's curved top framing for a basement shower.
After framing the basement the electrical work can begin.