here's Cuddles' power setup, it's pretty simple but it does the trick
the shield cell remains off until you need it - turn it on, fire it and wait for 5 seconds while it works, then turn it off again. your life support will cut out during this time, no need to panic.
same deal for the discovery scanner and kill warrant scanner - you don't need them both at once, so switch them in/out as needed
sensors are on priority 1 because often the enemy who damaged your shields is the same one you have targeted - so we don't want to lose him, as after we have fired off our shield cell we want to go straight back to him and smash his bloody face in. priority 1 makes sure you don't lose your current target and his subsystem target
an adjustment to the above pic - setting the FSD to 3 instead of 4 is a better idea.
as for fire groups, i use two - the first has both lasers primary, ADS/KWS secondary - the second has both lasers primary, chaff secondary
...good luck and have fun