well, my best fly on the perch is olive damsel tying from olive marabou with big conic gold head. Best time - when perch eat - before sunshine or 1-2 hours before dark come. If they eat fry you will see how they push fry straight to bank. This is probably the best time for fishing.
Perch is a cannibal so try some imitation of perch. I caught perch only on lures.
Smaller perches move together. Big perches live single and is difficult catch them - imitation perch with some red spots by head. All of them like shiny points
on your flies.
Good luck