Below are explanations and videos to view a streamlining land exercise, back float with flutter kick, and a simulation of the 4 swimming strokes.

The video at the link below has a drill to practice streamlining on land. An explanation is as follows:

Start lying on your back in a streamline position. Now raise your feet, hands, head and shoulders off the ground.

Using your hips roll yourself onto your stomach WITHOUT letting your feet or hands touch the ground.

Continue this a few times in one direction and then switch. Keep your feet and hands together at all times, focus on just using your core and hip rotation to get the job done.