Accelerating foliage placement

I just want to ask - How does one get a custom piece of foliage to show up as procedural flora? I haven't worked it out yet, and I haven't found any informative tutorials.
With the RW enhancer, is it practical to use procedural flora for portraying dense foliage (IE through drawing over an existing terrain texture?) Or do I have to resort to the tedious task of placing hundreds of asset blocks instead?
With the RW enhancer, is it practical to use procedural flora for portraying dense foliage (IE through drawing over an existing terrain texture?) Or do I have to resort to the tedious task of placing hundreds of asset blocks instead?