A super neat thing to do using a long shutter speed.
You can draw whatever you want mid air with just a light source!

To do this, set your camera to shutter speed priority (S) and set however much time you think you will need!
This is also possible on some phones, on samsung go to more > pro mode and find the fraction.  That is your shutter speed in a fraction of a second OR in seconds depending on your desired setting!

Photos were taken using both a Canon D2000 and a Nikon D3100