There are times when I thank heavens for jeans. As a general rule I live in skirts and dresses, but there are just some mornings when I reach for the nearest pair of jeans, a simple t-shirt, and head off on the school run. There are also times when the weather isn’t great, and a night out involves slightly more walking than just car-to-bar, and that is when the old staple of jeans, heels and a pretty top comes into its own. This weekend I was in Blackpool, and a night out consisted of a long walk along the promenade, making the most of the good weather, then a few…