You need to get Hyrbid Penetraion. Cause otherwise you won't be able to double penetrate b*tches.

So, what you wanna do with Thresh. Is just slapping b*tches all day long. You're against a leona? Slap that b*tch. Against Annie? Don't, it's inappropriate.

You just got to right click and max flay for a good whip.

Pros:

Flay making op
Slapping all day long
Making them your b*tch makes you feel awesome

Cons:

You can't slap your teammates. So don't be too distracted when your ADC is a woman.

Farming is bad. Minions are not worthy of getting hit by your chain.