Create professional looking graphic designs for your presentations and portfolios with Canva. Canva operates on a freemium style model: some of the images are free, and some are available for $1, which you pay when you publish.
The site has more than 20 tutorials to help you learn how to create attractive designs: cropping techniques, color palettes, and more.
And you can collaborate with your classmates: when you publish your design, click to make it editable by others and then share the link with your project partners.
If you use only the free images from the site, or your own images, you can publish and download your resulting image or pdf for free. I used one of their templates and my own photo and made this one in about 2 minutes. Very, very easy and a lot of fun to use.
And then I tried using the same photo for a header for my Japanese language learning portfolio:
HT to Shuhei for introducing the site. Thanks!