As soon as any accuracy is needed, AutoCAD for 2D and/or Blender for 3D. Blender is usually enough, but I'm faster in AutoCAD.
If possible, I try to physically experience the new space or object, using my imagination and any props at hand. For example, I might put masking tape on the floor, following the layout of the drawing, and walk around them pretending they are obstacles.
Tech is usually way more cumbersome to use.