First off, most of this is knowing the skill set of the person you are working with. We had a talk about how small I could make lines and what is easier vs harder to cut out. There is also a massive thick seam that runs along the center of all of them that is the bane of my existence and the hardest part to work around.
So, I have a tank and I have an idea in mind. If it is a pattern I will usually start out my measuring and cutting myself out a stencil just to keep it cleaner. The paper stencil shown here was the one used for the blue cloud tank. Most of the time however I am freehand drawing them. Now, I do not freehand draw perfectly every time so I have some water color kids markers I use for my initial design. After I finish and like it I go back over the whole thing with a sharpie. Then I spray it down with any spray cleaner, wipe it off and have a tank ready to go for Scott.
And lastly, I usually just show each tank to him and talk to him about them before he gets going just to make sure we are on the same page. Currently we are waiting for new welding tips to come in the mail and when they do I will be uploading finished pictures of these pieces this weekend for the curious.