Albie and Bonito Flies
Albies and bonito can be extremely picky. There are times you can cast at them all day and only with the perfect presentation and offering will you get a bite.
Have a selection of colors and shapes when chasing hardtails. They use those big eyes and at times will happily reject anything other than the real thing or something very close to it.
If looking like everything else they're eating isn't working, consider changing to a bright or different color, or a pattern that DOESN'T match what's in the water.
Sometimes being different is key when your fly looks like everything else.