Shooting a star trail is an excellent way to create amazing images on clear nights, especially when the best composition faces north rather than south (Milky Way).
You only need a camera, an intervalometer (built-in or stand-alone), and Photoshop (or another software with layer support). Simply take repeated 30-second exposures for numerous hours, then blend the images in Photoshop using the Lighten blend mode.
Any questions about star trail photography? Let me know in the comments below!