One of the best things you can do to set the tone of a blog post and encourage people to read beyond the heading is to include an image. Most bloggers understand this, because an awful lot of them use images in their posts. But “misuse” of images is more common than “use” of images, if you have the perspective that the purpose of an image in a blog post is to communicate.
Here, then, are 6 rules (I could have called them guidelines, but then no one would argue with me) for using images in your blog posts which deserve a yellow flag when violated:
1. One image per post.
Blog posts are usually short; 300-800 words is a commonly suggested length. That small amount of text simply does not create enough screen real estate to accommodate several images without looking cluttered and unreadable (you DID want people to read your post, right?). The idea of "less is more" has never been more applicable. In cases where multiple images are truly called for (e.g., you have a series of photos showing attendees at an event), you can use one anchor image with a link to launch a Thickbox slideshow (or similar). This is also a good technique to use when you need a large image to show critical detail.
2. Put the image at the top of the post.
Put the image where visitors can see it immediately, right below the heading of your post. I personally like to align the image to the right at the top of the first paragraph: the image is where they can see it and connect it to the heading, but it doesn’t block their entry into the post text as it might if it were aligned left.
3. Make sure the image relates to the heading of the post.
An image should not leave your readers wondering what the connection is with the post, either before or after (or if) they read it. The image should immediately and clearly support or illustrate an idea in your post heading. Most people view disconnects and non sequiturs as annoying, rather than intriguing. If you can’t find an image to relate to your heading, consider changing your heading.
4. When looking for images, bring along your sense of humor.
A little humor or irony in an image (as long as it’s obvious: reread no. 3) can draw people into the post. It’s a bit like telling a little joke before a speech. Of course, if the "joke" is inappropriate or misleading, then you’ve created another issue. So don’t do that.
5. Crop and size images appropriately before uploading.
Any time you see an image that seems to take forever to load in a post, chances are you’re looking at a big image that has been scaled to fit, rather than sized to fit (i.e., the blogger uploaded a 1200-pixel-wide image and scaled it down to 220 pixels wide in the blog editor, instead of resizing the image to 220 pixels before uploading). Get an image editor and learn to use it to crop and size images, at minimum.
6. Don’t use clipart or stock photos. Unless they’re pretty good.
A lot of clip art and stock photography is trite and awful and over-used. But some of it is clever and very good and it perfectly illustrates your concept. Put your photo-editor hat on and refuse to use the former. Under no circumstances should you use an image of a multi-ethnic and gender-balanced group of young people with perfect teeth dressed in business casual gaping in awe at the screen of an open laptop in a brightly-lit conference room.