One of the most used tools I have in my kit is an Ecomap. An Ecomap is a graphical representation of the systems at work in a person or groups life. The graphic places the individual or group in the centre and all the other groups or individuals which have influence over them. This great tool has been in use since 1975 when it was invented by Hartman.
The basic idea is that you draw a circle and put the client in it. You then draw circles around the outside which represent the groups and people involved with the client. The reason this is one of my favourite tools is that it shows the people and groups which have influence, whether good or bad, over a persons life. This can then be used to discuss positive influence and the need to deal with negatives.
give it a go.