We're reaching the 50$ bottom, last time, this was where ZEC got some support and went back to almost 0.14. I think that selling everything now isn't smart.
Personally I'll keep mining until I'm not getting any profit out of it which is around 30-40$/coin.
Wait and see...
This is the point I am currently at. All through the slow start I sold every ZEC as I mined it as the profits were good. I am just now starting to transition from selling everything to keeping and holding some ZEC.
I am currently at a 75% sell to 25% hold ratio, but over the next month as I think the price will start to stabilize more and I will convert to selling enough to cover power costs and holding on to the rest, probably ending up with something like 75% keep and 25% sell.
When the revenue of the mining is more than 2 times the electricity cost, it is better to sell. Otherwise, it is better to hold.
For most people, it is less than 2 times of the electricity cost, but the price is still going down a lot.