Direction of flow, flow rate, output temp ?

[CROW-EATER]

I am running a offset head still, 2" column, 3" condenser with a double wound cold finger coil.

Can someone please clarify for me, in which direction should my water flow through my coil and more importantly, why ?

Should I be aiming to have the water exit at a certain temperature or is it best to pump as much cooling water through my coil possible therefore keeping the temperature of the coil as low as possible over its entire length ?

I'm pumping my cooling water from and returning it to a big rainwater tank so wastage is eliminated.
I have several types of 12 volt pump at hand, all with different flow rates and I can meter my flow rate with a valve if necessary.

Cheers