I usually just prop the mirror up on a table, set a white background object about 45 deg to it, stick the camera between them so the mirror is reflecting the white surface, and click (crick 'its a Fuji' ) take the picture.. In the one below, I used a piece of styrofoam board, not the best choice because you can see the stippled uneven pattern in the reflection.. It look like I was getting banding in the etch but nope, it's all in the background..