Most kokanee are taken on small lures or bugs trolled either by themselves or behind a kokanee dodger. Kokanee are attackers. Some large solitary fish are very territorial. They will attack strange intruders as long as they believe they have the advantage. If kokanee feel they are outnumbered they will stay away from your lures. In some bodies of water you will find kokanee tightly schooled. In others they will be found almost one by one.
Kokanee are unlike any other fish. They are primarily plankton feeders, and also feed on tiny mysis shrimp. Since they do not readily feed on minnows, lures or standard bait, kokanee must be targeted specifically. Larger kokanee are very territorial. Kokanee are attackers. What triggers this attack seems to be the right style of lure in the right color for the moment. Corn and scent seem to be the final key to triggering an attack.
The material presented here will give you some proven guidelines to follow for taking kokanee. However, kokanee can be very unpredictable. What works one day may not work the next. If your marking fish and not catching them don't be afraid to experiment. Good Luck!