‘Body Position’ is not a static concept. It’s dynamic and swimmers...

Pressing the ‘T’ is a common suggestion in freestyle for effective body position, and while it’s not wrong, it’s incomplete.
Here’s a simple, introductory option for helping swimmers learn this skill.
From a floating position, have them move their arms up and down like performing a jumping jack.
Body position is a dynamic skill, and swimmers must be able to maintain effective position at high speed.