A lot of it depend on the level and committment of your team mates. You can mix and match on the day planning wise, or you can plan to quite a good detail. I would suggest that early on everyone works on their core skills eg batters bat, bowlers bowl, but they should be encouraged to develop a second string, so batters should be able to roll their arms over in a game if required, also how often does a extra 30-40 runs from 9 10 and 11 make a difference in the overall result.
In a two net scenario:
I would have an established batter in one net, with fast bowlers and seam bowlers in that net with a bowler batting in the other against part timers and spinners. Have each player working on two specific skills and be responsible for monitoring that through the net. Important they can assess it post net.
Then just rotate the batters and do the same thing, I reckon 7 mins per net and swap. Key is to keep it sharp and focussed. Too often guys bat too long and loose the intensity.
Am open to helping guys out. HAve played up to first class in NZ and been a pro for clubs in the UK and been in charge of junior coaching at schools and clubs so pretty well versed with net issues. Key is to mix it up try things every now and then to keep it interesting.