I hate self tacking jibs, they are only any use when gybing downwind in a breeze. Too many people set them when they round the leeward mark and don't touch it again until after they have hoisted the kite at the top some 5-10 minutes later!
Both sails need triming every time the wind fluctuates and every time boatspeed fluctuates - like out of a tack

Another thing, when there is bit of breeze, get the crew to ease a bit of downhaul as he/she comes in for the tack, to give a bit more power out of it.