First snaffle, then halter, then rope ... The important thing is that they really need to trust and respect you before, and to be able to understand your voice's orders and your back/legs codes.
Most of the time the first time I keep the halter or snaffle on and take the rope asking for very easy basic exercises (turning, halt). When this is safely understood (usually after 2 minutes !), then I just put everything away and keep only the rope.