Thank you Gidde.
That wall is the first time I've ever tried drawing anything on the tablet that wasn't just a few small lines or some shading. I found it very tricky, especially as the wall is far longer than my screen when zoomed in at a comfortable drawing size, so hard to gauge direction etc. In the end I just had to learn to embrace the roughness.
The tablet has a learning curve for sure but I really am loving it.