That's one reason I really like Visual Thinking Strategies (VTS). We've incorporated VTS into many of our lessons that require image analysis and for the last several years colleagues Deb Mitchell and Jim Schulz have conducted trainings on this technique across the state.
But there are many other tools to help students slow down and really look. Among them is Crop It, a simple "four-step hands-on learning routine where teachers pose questions and students use paper cropping tools (template here) to deeply explore a visual primary source." The website Teachinghistory.org, where I first learned about Crop It, handily offers a question set for teachers to use with this tool, suggesting such questions as:
Crop to show a what first caught your eye.
Think: Why did you notice this part.
Crop to a clue that tells when this is happening.
Think: What helps us recognize specific times?
Crop to a clue that shows the emotion expressed in the image."Zoom-ins" are another approach. TPS-Barat's Primary Source Network published a series of guest posts about this technique--all with different examples. According to Social Studies Specialist Patti Winch, of Virginia, Zoom ins were originally created using PowerPoint. "The first slide of the presentation would show one small section of an image and teachers would ask students to identify what they saw. Subsequent slides revealed more and more of the image, asking students to identify ‘new’ things that they saw." More recently, though, her district has been using Google Forms to post image details AND questions that students need to answer.
Think: How do colors, lines, and shapes express emotion.
Museum educator and sixth-grade Virginia history teacher Alissa Oginsky took direction from the Library of Congress's primary source analysis tool when she created her Google Form Zoom-in.
And seventh-grade history teacher Sara Conyers, also of Virginia, provides step by step instructions for creating a "Zoom-in primary source analysis activity using Google Forms here.
I use Google forms a LOT--for example, to gather responses to our end-of-the-year survey and find it an extraordinarily useful and easy to use (which is saying something as I'm not the most tech savvy person). And speaking of our end-of-the-year survey, please take a few moments to participate. It really helps us improve.
P.S. You can find more ideas for using Google Forms, including creating self-grading quizzes, over at Glenn Wiebe's HistoryTech blog.