Do this until your result is achieved. What is most important is to know the person's name. This is usually inscribed or written onto a doll, candle, etc. Some physical object from that person which carries his or her vibration is also a very powerful tool in this work but not required. There are intense emotions associated with the image of someone we know.
Any magical tool is subject to vibrational changes depending on how it has been handled.
Most need to be re-charged through ritual or meditation periodically with the phases of the moon. In this way each magical item is truly a living thing. They also can absorb negative energies from the people who have used them in a questionable manner. This is why you should never use someone else s magical items. If you do you will probably feel the effects immediately, although in a subtle manner.