This is the obstacle I ran into this last month with our oldest daughter. She had drawn out some thumb nail sketches for me after verbally describing them to me, I had not clue what she wanted. I have seen this happen many times in the past when one person is a seamstress and the other person doesn't know sewing terms or fabrics.
So how did we resolve our communication difficulty. I drew up a Croquis with my daughters measurements in mind. If you are asking what is a Croquis? It is a quick sketch of a fashion figure. There are many good tutorials out there on how to create them. Taking the time to draw them is absolutely worth your time and effort.
After drawing a croquis of our oldest daughter, I took a blank piece of paper and laid it on top of her croquis. I sketched out different versions of what I thought she was saying she wanted. Each design was on a different sheet of paper. I also added a few extra drawings in different cuts that I thought she might also like but since she doesn't know enough about sewing yet might not think to ask for in her design.
This method made it so much easier to communicate about what she was picturing because she could say things like, I like these lapels, those buttons and could see where the skirt would hit her legs without having to cut or sew anything. This is fantastic because as usual I am on a time crunch and don't have enough of the final fabric to do several versions of it.
Here are some of the sketches so you can see what I mean.
