Sounds like you may need to learn some more mechanical skills.
The milage of you car would be helpful.
Assuming your air filter is not restricted smoking is caused by things that keep the fuel from burnig well. Worn Injector Spray Nozzles not atomizing the fuel well, low compression, the valves being out of adjustment and the timing being off.
Of the bunch the Valve adjustment is the easiest to deal with.

Does the Idle smoke go away after the Engine is up to operating temp?
Does you car start easliy when it is cold?
When you have the idle smoke does it puff out or smoke continuously?

__________________
84 300D, 82 Volvo 244Gl Diesel