Being a saltwater angler, sinking lines and sink tips are a way of life. I'm so used to them now, I actually prefer to fish with them.
In freshwater I use sink tips mostly for streamer fishing the bigger rivers, like the Del in NJ or in the 'skills; places where I can get a good long drift in water over 5ft deep. The chuck-n-duck method is not needed if you use the correct weight tip for your rod. You should be able to cast the sink tip almost the same as you would a floating line. Getting to know when your rod is loaded correctly, then shooting the line with a minimum of false casts, is the way to do it. It takes practice, but is a good way to learn how to cast any line, not just sink tips or shooting heads.
On a 5wt rod you shouldn't really use more than a 150-grain (or so) sink tip to fish comfortably. Of course you can always use more if you want, but then you'll be ducking
. I've used a 300-grain on my 3wt, but that was very unwieldy to say the least. It worked, but not comfortably.
A short leader, no more than 5ft, is enough. A straight piece of line will work, no tapered leader needed. 6lb, 4lb, whatever. Unless you're using a weighted fly as well, fluorocarbon is the better material to use because it sinks. Mono tends to float up.
I fish sink-tips just like I'm fishing a run for salmon. Cast 90* out or even 45* upstream depending on depth, then let the current swing the line downstream until it's directly below you. Hold it there for a while and let it sway in the current, then repeat. I've gotten many hits on that swaying motion at the end. You can dead-drift and mend, or you can tight-line swing, depending on what action you desire. If you're not getting caught on the bottom every now and then, you're not fishing deep enough.
BTW, most bigger fish and baitfish tend to hang down near the bottom.