Here are some tips and great resources if you are interested in planning a photo walk for yourself or with your students.
Apple organizes photo walks where you can sign up to join a group that is led with a certain focus for the planned photo walk. For example currently in the Grand Rapids area there are upcoming photo walks focusing on Street Photography and Manipulating Light and Shadow this month. In the Ann Arbor area they have planned photo walks that focus on Capturing Action and Video, Street Photography, Telling A Story in Your Photos, Portraits and People, Developing Your Style, and Manipulating Light and Shadow. There are several other areas around the state where Apple stores are organizing additional photo walks.
PetaPixel's website features their Seven Commandments for Great Photo Walks. These include things such as introducing a constraint to boost creativity, always walk somewhere new, and you should trust your instincts when it says a photo must be taken.
One way that I've done this with my photo students at the beginning of my Digital Photography class was to go over the basics of photographic composition and then get outside around the school and start trying to shoot with those principles in mind. With my beginning studio class I would have my students do an Elements and Principles walk. We'd go over the E's and P's and then go out and seek them in the world around us whether it be in the school or outside on the school grounds.
Here's a great resource to help you plan photo walks in your city. It includes information about preparing for a photo walk as well as wonderful tips for how to make the most of your photo walk.