Another try using watercolours. This time I also used ink and brush for the lines (except the text, I used a fineliner for that).
I painted the watercolour with broader strokes, which makes it a bit better than my previous attempt, I feel. Still a long way to go before I can achieve an anything like this (probably never, but that’s OK).

Maybe I should do the lettering afterwards with a font on my computer . . .