Autonomous agents can help users by taking on a substantial workload, and performing tasks that are too complex for a human. However, in some systems complete autonomy is undesirable as it removes control from the user. It is therefore important to include some user control while maintaining the reduced workload associated with an autonomous system. This is particularly true of user avatars in virtual worlds, appropriate non-verbal communication is too complex to be directed explicitly and should therefore be controlled by an agent. However, the non-verbal communication should express the feelings of the user, so a degree of human input is needed. This paper presents Demeanour, an autonomous system for generating body language in avatars, which integrates user input based on a three level methodology of customization and control.