I personally use my own machine in training. I tend to do 2 hour sessions.
Usually I generally do 50 balls on each shot. I literally start off with full and straight, full and on off stump, full and on leg and hten full outside off.. then pull the length to 'driving ont he up' and go through the leg, middle, off and outside off.. then pull it back to a good length.. do the same... (carry this on until you are basically pulling and back foot driving.
Then I move onto cutting. Specifically I play late cuts, cuts through backward point, point and then through covers to ensure I can (try at least!) pick when I put the ball.
That's what I've found personally the best way to do a 'general' session as it goes through the full range of shots. YOu can add spice to this if you have a feeder person as they can throw in 'random' balls to keep you from pre empting the machine etc.. that adds a bit of a challenge to it.