designer has 4 steps which i follow
1. i m think about model or any object which i want to make.
2. then i sketch that model on paper in 4 views (front, top, left or right,bottom)
3.then i give dimension properly.
4. then i make my 3d model.
Try to observe physical bricks machine which you can access...Then make dimension on the paper. Arrange drawings of standard bricks machine, then develop it.