This Creeping St. John's Wort - Hypericum humifusum - appeared at the edge of my vegetable patch. I have no idea where it came from, because it's a plant I have never found anywhere on my regular travels.
This next image is a perfect illustration of a key factor in moth identification: pattern comes before colour. This is the Flame Carpet - Xanthorhoe designata, and it should have a red/orange band in the centre of the wing. It took me quite a while to pick out the key identification features in the absence of the normal, bright colouring.
The process of moth identification is unusual in that even at the macro level, species can be difficult to separate. Many families of insects, fungi and some plants need microscopic analysis to separate them, but the trick to moths is knowing which of the macro features in front of you are the critical ones. Simply comparing pictures isn't going to lead you very far. In this case, the key features are: the twin rearward-pointing, blunt, points of the dark central band, the dark leading edge to the central band, and the overall rather equal split of the 4 wing bands: dark-pale-dark-pale.