Something that's been sorely missing from my 15mm terrain collection are trees, or at least ones based in small groups (I've done a few individual ones).
My budget doesn't stretch to the nice flocked peces, so I bought in a couple of bags of some cheap plastic ones.They look plastic-y to start with, but given a spray of Green paint the foliage looks better. The spray does colour the trunks as well, but this helps disguise the gaps in the canopy. The trunks were sprays brown and dry brushed with grey.
These have been hot glued to some Renedra Oval Bases and given a routine basing treatment.