Does anyone have a tried and tested method for greasing fluted cake pans so that cake doesn't get stuck when you're trying to turn it out?

I made a yummy cake only to lose a quarter of it because one part stuck. It happens 3 out of 5 times, but I don't want to give up using it, as I've only had it for 6 months.

I've tried spraying with oil, greasing with butter, greasing with butter AND dusting with flour...