Freepik is one of the most famous websites for free resources and premium graphic design resources. It consists of Illustrations, icons, vector graphics, and Photos.
Unblast is another popular website for graphic design resources. It provides free and premium mockups, Icons, Fonts, Templates, and Graphic elements.
Mr.Mockup is one of those websites that has a separate section for free mockups. You can also purchase mockup bundles as well.
Vecteezy is another popular website that consists of Vectors, Photos, Videos, and mockups.
Free Design Resources provides completely free design resources from fonts to templates. Everything is free.
Colorlib provides free and premium WordPress themes, Website templates, and Bootstrap Templates. They have been active since 2013.
Font Squirrel has a collection of 100% free for commercial use fonts what you can use for your next project.
The fonts presented on Dafont are either freeware, shareware, demo versions, or public domain.
*note: before downloading a font do look out for the indicator that tells you whether it is free for commercial use or not.
Icons8 produce their own content from icons, illustrations, photos, music, and design tools. its one of my favourite sites for icons as it consists of a wide variety of options.
Pixelbuddha brings free and premium design resources of the highest quality. From fonts to effects they do it all.