For me, the FD was easier to get shifting just right. Disconnect the cable, set the low limit screw so there's barely a hair's clearance from the chain in the small ring-big cog combo, pull the cable snug, and reconnect it. The shifter indexing takes care of the rest.

I do think that some cranksets -- or maybe more specifically, some chainrings -- shift more cleanly than others. I switched from a Truvativ standard crank to Shimano compact as part of a warranty claim, and I think the Shimano shifts easier and more reliably than the Truvativ ever did despite having a bigger jump in tooth count between the rings.

(I'm not a pro mechanic, btw )

But, yeah -- when it's working properly, you'd sweep the shift lever all the way when you want to make the shift. Pull all the cable with the big lever, and release it all with the small lever. Also, in the rear, you can sweep the big lever to downshift as many as three cogs bigger (although each rear upshift still needs an individual click of the small lever). When I shift the front to the big ring, I use the same motion with my right hand to downshift three cogs so that my cadence stays pretty much the same.