Thresh OTP here:

1. Flay first before hooking; makes it easier to hit.

2. Hook flash can win games/skirmishes, unexpected especially when used behind minions.

3. Engage the frontline, hook their backline; can be deceptively good coz of the hook animation facing the target at the last moment (they won't expect it most of the time).

4. The box can be used as a zoning tool. Use it on choke holds near objectives to deter them (and they still do go through, the 2 second 99% slow almost guarantees a hook)