Once you have figured out how to do the steaming at all, you can work on limiting it and only streaming single scents, or only sounds, or things like that.

But it's easier if you concentrate on the streaming at first, and not on separating what you want and don't want to stream.

Like how when you start walking, you first focus on the getting to your feet and taking a step, and only later on the direction into which you want to walk.