Patent-Focused Machine Concept Sketches

I have a working prototype and a patent already issued on the concept. I am now preparing the follow up patent that was discovered as highly unique and patentable when designing the original prototype. I'm a horrible drawer but a great visual, verbal communicator. The beauty about these drawings is it will only focus on one key concept and one area of the prototype. There will be multiple drawings because while it's one concept - there are about 7-8 approaches that either alone or in conjunction will achieve the goal. The goal is not so much patent ready drawings, I just need drawings to the level my Patent attorney can turn over to their inhouse team. An NDA will need to be in place.