Seasonal strategies: the impact of spring, summer, autumn & winter on advertising

Every year presents a human truth: consumers will be inclined to spend more money during certain periods and less during others, depending on the products and services in question. As a marketer, how does one gear efforts around the peaks and troughs of consumer behaviour to deliver a strong year-long marketing strategy all the way from new year’s resolutions in January to the rush of Black Friday and the Festive period?