Shooting snowflakes are fun but can be challenging. For these shots I used a Panasonic GH3 and a Lumix 100-300mm lens with an old manual 50mm lens attached to it in reverse (face to face using a macro coupler ring). For light I used a small LED light source. The setup looked like this:

To properly see and photograph snowflakes, they need to be lit from a specific angle. I moved the light source around to get the effect I like while triggering the shutter with a remote.

As shown in this video, a very small change in the angle of light will have a dramatic effect.