Drawing the basics is really quite easy, it just takes seeing the steps and practice. Start with a 2D shape, like a square, triangle, oval or circle. If doing a prism or cylinder, draw a second congruent shape up/down and to the side of the first, then connect the corresponding vertices. Trace along the edge of a ruler between vertices for precision (or just to help young eyes and hands).
Students will need practice. Some students may need help making the 2D shapes. One way to scaffold is to make dots on the paper for them to connect first. Show all students how to use light pencil marks and an eraser to rid their drawings of extra lines they don’t want to see. Use this activity on its own and create artistic masterpieces, or use this activity in preparation for working on word problems of volume or surface area.
While your students will not be required to draw an icosahedron, a cube is going to come in handy. In addition to being able to make a cube on command, you may notice that students become more and more adventurous in their other drawings. Likely, students will play around with perspective and get a better understanding of the world around them. Also consider looking at composite shapes after showing students how to draw basic geometric solids either as a look back at what you already taught, or switching up the order.