Fish on the bottom before the hatch and in the surface film during the hatch.
Dun
AKA The Sulphur Hatch. Flies should be close imitations in the slow water. Comparadun and parachute patterns on #16 hooks are the best choice. Use fine tippet and cast softly onto the smooth surface. Dropping the fly onto the disturbed water of a rising trout is sometimes effective.
Spinner
Fine tippets, soft casts as above. Full spent pattern on #16 2x long hook.