Illustrations on websites are becoming increasingly popular and they're a really fun way to share info on your site.  Of course you could hire a designer to create designs just for your website, but what you may not know is that there are also royalty free illustrations available as well.  

Undraw

Undraw.co has a bunch of ready made illustrations available to use on your site royalty free and a search function that allows you to search by category.

For instance looking up yoga brings up these cute illustrations.  Once you've chosen your illustration you're also able to change the primary color so that it can match your brand.

Humaaans

Humaaans is a mix-&-match set of illustrations of people and backgrounds.  You can modify the backgrounds and the people to suit your needs. 

Free for commercial or personal use by Pablo Stanley.

Open Doodles

If you're looking for something a little off the wall, Open Doodles is a really fun library of characters participating in various activities.

Fresh Folk

If you're a little more advanced and have Photoshop, Fresh folk is downloadable library of illustrations that come in the .psd format that you can add to your designs.

 Some fun ways to show off the illustrations are the feature photo frame or the image with overlap text