The first sketch, which didn’t go well:
![Vase](https://devyse.co.uk/wp-content/uploads/2021/02/20210201.jpg)
The vase is titlted in relation to its base – why? Because I drew the main axis at an angle.Or the base is at the wrong angle. I only noticed when I scanned the drawing. I need an aid to check as I go along, like a transparent grid. It’s particularly important to use this aid early on, when I’m drawing the axes.