You may have noticed that A Guide to Profitable Freelancing gets by with articles that only has written text. That's because that was how I chose to differ from all the other blogs out there about freelancing.
But I would also be among the first ones to say that for the majority of blogs, "add-ons" are needed, to improve the clarity of the blogger's message, to drive home a point, even to provoke or catch the attention of online readers.
A word about add-ons, though: use them sparingly. Their main purpose is to enhance the blog's layout, not distract your readers from reading your articles.
Any of the following can be considered an add-on:
Some bloggers choose to upload color photos that they have taken themselves, while others come in black-and-white. Color photos can brighten up an otherwise dull or monotonous background, while black-and-white photos tone down the mood of bold and bright color templates.
Keep in mind that since it's your blog, you own the copyright to whatever you choose to publish. So needless to say, you should not steal someone else's photos and use them as your own.
Drawings, illustrations, or caricatures
I'm not just talking about graphic or multi-media design, but drawings rendered on pen and ink, or colored pencils, or even paintings. Blogs that lean heavily on marketing or deal with the subject of art and its impact on society may use these.
I have seen plenty of online marketers record videos of themselves and then upload them in their blogs. Usually, these videos run for only a few minutes, and the one "hosting" the blog will air a message welcoming new readers and then get them in on the basics of his business.