I've used waterproof, fine-point pen first, then the watercolour. The lovely, old York Stone of the house is great to paint, with its subtle colour-variations.
The previous owners planted a vine and I'm still amazed that we can grow grapes as far north as Sheffield. They are just beginning to colour:
The ivy too is changing, as the season comes to an end. One wall is covered with it and it turns from green to brilliant red for a week or so, before the leaves all fall. I switched to pencil, although found that the watercolour can wash it off if I'm not careful: