It is important to include detailed sketches in your engineering notebook. Remember, the notebook should be used as a tool. The more details you include in developing ideas will help you when you begin to build.
This is especially true if a team splits into different building groups, with one group building a chassis while another begins building the lift. Often students will struggle with communication about how these subsystems will integrate together. Make sure the notebook communicates this before you start to build.
Also, be sure to include motor placement in your sketches. Often students will build the chassis or lift and need to remember to integrate the motors when they build. Attaching the motors to metal is much easier before the chassis and lifts are built. Otherwise, you will take apart sections of the robot to integrate the motors.
Notice how text annotations accompany the sketches in the sample to communicate details such as gear size and motor placement.
CAD drawings are nice but optional. Some students prefer to use CAD because they find it easier to communicate their ideas. Autodesk Inventor is a software company that integrates VEX parts into its library. Check out the many Autodesk Resources and Free Software for the VEX Robotics Community.
Other CAD programs can be used, including OnShape or TinkerCAD. However, you will need to make your own VEX parts for Tinkercad. You can file CAD part files in the VEX Store or in the VEX Forum.