
Chest on chest, head to their hips.
North-south is a pinning position where you lie chest to chest with your head towards their hips. It is often used as a transition from side control, and it has its own submissions: the north-south choke and the kimura.
Keep your weight on their chest and your hips low, and move around their head to follow their escapes. From here you can return to side control on either side, take the arm, or finish the choke.