As a rule of thumb, the width of the shade of your picture light should measure approximately 1/2 the width of the frame or artwork below. For best results, position the light at a 30-degree angle from the illuminated artwork.
Beside the Bed
If your sconce has a switch, be sure to install it where it can be easily reached from a sitting position in the bed. For best results, leave approximately 55"- 60" of space from the floor to the top of the sconce.