Experimentation is key. A standard sized coaster of realistic dimensions will usually take me about 12 (or more) hours to set the waypoints using colored prims; then I must move the car (position + rotation) to each of those prims along the track and 'add point'. I do them in sections... I always say "It takes a lot of love and patience for the artist to get that beautiful ship inside the bottle". If you have the patience, you will go far.