And remember that perfection is the enemy of the good. I needed a little bit of drafting to design a sun room and started looking at software options. I didn't immediately like anything so I grabbed a ruler and a piece of paper and drew what I wanted pretty quickly using the standard 1/4"=1' scale. Precision is actually unimportant, everything will need to be fitted by the builder in the end, even if an architect measured and drew everything in AutoCAD/Revit. But very quickly you can get good results without even a drafting table and T-square. I have the T-square and triangles, but didn't have the space to work with them, and I'm happy enough with the result.