Social media posts that use creative graphics are more likely to engage your audience. However, unless you have a graphic designer on staff these well-crafted posts are hard to create. Enter Canva, a web based graphic design service. Canva offers a vast array of free images and templates, as well as a library of one images available for a one-time fee of $0.99. They offer design tutorials that are quick and informative, definitely check them out.
Do this:
Go to Canva.com and create your free account. Either click the type of media you want to create on the top or check out the design tutorials. I recommend the Beginners Challenge and Essential Canva Tools.