Snappa is a great tool for all your design needs. First of all, each image has formats which can be used for social media, web design, blogs and headers, so there’s no time-consuming cropping necessary. Secondly, the pre-made templates are very high quality. Thirdly, the library of stock images, graphics, fonts, vectors and effects is packed full with non-attribution goodies. It can be completely free, or low-cost. A really nice piece of kit!