Specifically the straight threaded inlet at the back of the block on 94-95's but also in general for tightening lines down on fittings on the turbo. I'm assuming you shouldn't crank it down with all your strength, so how much?

 

For BSP and NPT threads you should be using a thread sealant, like teflon tape or paste. I tighten my fittings until they're tight which means grabbing the wrench closer to the center and turning till it stops. That keeps me from over tightening them, at least that method has worked thus far.
Do not overtighten aluminum fittings, especially the one that goes in the block, Scott broke one off in there that way.