Thought it might be useful for others learning to use DCs to see what a DC newbie has learnt. I may post further updates as I learn more.
Lesson 1 - A DC will normally comprise a main component (parent) and sub-components (children). Keep the geometry of sub-components as simple as you can.
Lesson 2 - Include controlling dimensions of sub-components under the parent. Sub-component dimensions should then refer to these controlling dimensions. This is to ensure sub-components scale correctly (or more usually to stop them from scaling when the main component size changes).
Lesson 3 - Axes are crucial! You may have to reset axes for each sub-component so that its position and orientation behaves in a predictable manner. Conventionally, you would have the main component origin at 0,0,0 and the positions of all sub-components would be related to this.
Lesson 4 - When filling in the parameters of each component, click the button to display functions. All parameters that you want to control should have spreadsheet formulae in them.
More lessons to come perhaps!