My FD diesel throws out an amount of smoke most noticeable at night when I pull away from stop. I notice white smoke in the mirror highlighted by lights of car behind. It has done 270000km but  it has been noticeable for a long time.
Not using oil.

[Banks]

My i30 crdi smoked on startup and under full throttle. I could actually make massive plumes of smoke when getting tailgated which I enjoyed thoroughly  .I ran a bottle of Nulon diesel injector cleaner ($14 from Supercheap)in a few tanks of fuel and this partly fixed the problem.  Could also be the glow plugs . Only 2 of mine were working after 100000km. I purchased a full set of NTK ones from Korea for $70  about a quarter the price they are in Australia.
The glow plug relay can also get a build up  internally from the contacts arcing , there was a forum post someone did about this and I followed their instructions and took apart the relay and sanded the build up off. This could make the the car smoke on startup and the first ten mins of operation .

[Lorian]

Double strength as per the bottle - if you can get it there.