I use a small (cheap!) mp3 player with the manuevuers on it, and have opened it up and fitted a small microswitch to the FF button, so that when I want the next maneuvre I touch the button with my pinky, and off we go.

When I recorded the schedule I read the schedule, and waited 60 seconds in silence. This gives you time to do the maneuvure once or twice without the schedule skipping ahead of you.