Body shapes are the foundation of tumbling skills - think of them as the ingredients, your drills are the recipe, repetitions are the oven and the skill is the cake!
Even when you can't tumble in the gym, shapes can still be practiced and perfected at home. I've created a poster of the essential shapes that you can train at home and you can download it for FREE.
Remember, everyone has different names for tumble shapes so they might be called something different here than what your coach calls them. Make sure that you point your toes, keep your arms straight and squeeze :)