Must be at the right place at the right time.
No secrets.
I use the same setup every trip.
Some days I don't have much luck.
Some days I hook them and loose them all.
And some days I bang em and land them no more than 3 casts.

I've seen eggs out fish shrimp.
I've seen shrimp out fish eggs.
I've seen all colors of corkies catch fish.

Just stick to your favorite rigs and keep on casting. The main thing is your confidence and concentration.