I am tutoring a couple of students in high school physics and have for the first time come across the problem of how to teach high school students the basic concepts of relativity. I explained the MM experiment and they found that comparatively easy, but upon getting to time dilation they started to get confused. As most people I assume do upon first coming across it, just as I did a few years back. But I was wondering what are some tips on the best way to teach this? Stay conceptual, or introduce some paradoxes then explain how they are overcome, or go into equations? I have only covered MM and then time dilation (using the concept of a light clock) both of which served as a basic intro to the frame of reference concept. I was then going to cover simultaneity then length contraction finishing up with mass changes. Is that the best order? The students are expected to know, and apply, the Lorentz factor for length contraction/time dilation/mass change. However no Minkowski space, or velocity addition. Any help would be greatly appreciated.