As there are more ways to make trees than there are rulesets to play in 28mm...
I did some research, as always, and finally decided that these two videos were what I wanted to replicate. The first is by an Aussie (?) who is clearly a master woodworker and into making terrain "on the cheap". The second is a more conventional project.
I made the jig from the first video for pines, and hand-twisted wire trees to replicate the second. I hope to have something to show soon.
As mentioned, there are so many other worthwhile tutorials out there - here are a few more.
This is a great option for Wargaming trees, as opposed to some of the more complex "train terrain" versions out there:
http://www.beastsofwar.com/terrain/terrainscaping-awesome-tabletop-trees/
This is a neat series about one modeler's attempt at trees
http://troubleatthemill.blogspot.com/2012/11/into-woods-part-1-bases.html
http://troubleatthemill.blogspot.com/2012/11/into-woods-part-2-undercoat-and-scatter.html
http://troubleatthemill.blogspot.com/2013/01/into-woods-part-3-foliage.html
http://troubleatthemill.blogspot.com/2013/01/into-woods-part-4-more-ways-of-sticking.html
http://troubleatthemill.blogspot.com/2013/01/into-woods-part-4-slight-digression.html
http://troubleatthemill.blogspot.com/2013/01/into-woods-part-6-another-slight.html
http://troubleatthemill.blogspot.com/2013/04/into-woods-part-7-willow-trees.html
http://troubleatthemill.blogspot.com/2013/04/into-woods-part-8-magic.html
A simpler blog:
http://paint-forge.blogspot.com/2015/04/how-to-home-made-trees.html
This link has a really cool way of making trees from aquarium plants - he wrote it for 15mm:
http://18charlie.com/15mm-trees-part-one/
This gent in the UK models for 28mm, but his scenery is gorgeous:
http://wargamingwithsilverwhistle.blogspot.com.ar/2015/05/trees-orchards-buildings.html
These guys do a cool series of How-To's - the 6mm version is featured further down:
http://www.architectsofwar.com/Howto/BigTrees.pdf
A really good option that uses steel wool (I tracked this one down after reading the one above...)
http://archive.brushthralls.com/terrain/tree-templates.html
This is more for dioramas, but the concepts are the same - and since I'm currently working on a diorama for my wife, well...
http://fantasygames.com.pl/blog/making-trees-tutorial/
And for realism over usefulness:
http://www.fcsme.org/bcarl/how_to_make_scenic_express_supertrees.htm
Some articles scaled specifically for 6mm, or for "Canpoy"-style groves:
http://www.6mmacw.com/forests.html
http://www.architectsofwar.com/Howto/forests.pdf
http://1000footgeneral.blogspot.com/2011/06/megawood.html
http://verytinywars.blogspot.com/2014/11/making-3mm-forests.html
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