Crystal on a wall is seen at close range and at eye level, so the cut is under more scrutiny than it is on a chandelier. Fit crystal wall lights in pairs, at about 1.5 to 1.7m to the centre, and match them to any crystal chandelier in the room by maker and finish.
Crystal needs a real source to work on, so a small, bright point of light gives more sparkle than a large diffused one. Dimming matters too, as crystal is easily overpowered at full output in a small room.