Draw the cup you're holding this morning, or the shadow it leaves on the table. Notice where the light sits on its rim, and where it gives up.

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.

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.