I'm starting to become happy with the results from my "tree skill builder" exercise. Here are a cluster of three trees that I'd have no problem putting on any layout. There are couple minor variations in them, but the only noticeable is the trunk color. The brighter one in the middle is Builder in Scale's "Brownwood" stain straight from the bottle. The other two are Builder in Scale's "Blackwood" stain drybrushed with raw sienna acrylics.
The biggest thing I've been fussing with is branch color and flocking. Here's what I've settled on:
I'm using a blend of fine and course foam, 4 parts fine to 1 part course, colors leaning on the medium to dark green side. After flocking I airbrush the trees, 2 parts Pullman Green to one part Coach Green (Polyscale/Master Modeler brand paint). The underside of the branches are then given a light wash of one part Pullman Green to one part Rail Tie Brown.