Could somebody explain me proper way to make drawing (from assembly) and exprort it to dwg format with layers?

Should I for each element define layer and simply save as... or maybe better way is do it with mapping file?

On the dwg file I need to have standard layers (main, dimension, notes, centerlines and so on).

Its possible to define separate layer for some parts in assembly (i.e. pipelines)?

Can you share your drawing template as sample?