Draw the cup you're holding, or the one nearby. Notice where its shadow lands on the table and how it softens at the edge.

Try drawing a single mug or cup near a window today. Notice where the light lands on its rim and where the shadow pools underneath.

Sketch the cup you're holding, or a shoe by the door. While you draw, notice where the shadow pools underneath it, and let that dark spot be the first thing you put down.