Exercise - Basic shapes and fundamental form

I found demonstrating fundamental form drawing jugs and jar more natural than implementing the books and boxes. I found that it was hard to get the proportions correct and the lines didn't seem true to the boxes and books in front of me. The jars and jugs were for me easier, I started with pencil and continued with ballpoint pen once happy with the shapes. Over all I found these exercises difficult when trying to demonstrate distance between the objects and achieving depth.