This taster pack contains deciduous and conifer tree assets, in a variety of clumps and single trees to enable faster and more efficient creation of forests. They also look pretty good.
Using these assets will result in significantly less tree assets in your map, which should provide big performance benefits. It should be quicker too!
(Thanks to jchunik for the asset counter, and the water texture used in the map above)
A more full pack is under way with a much greater variety of forest types, but for now this is what you can have. The final set will be available to purchase, and as a cut down free version.
I recommend using the loose clumps to create a border around your forest and the dense clumps to fill it in. Loose clumps can also be used for more open woodland and surrounding trees.
Using smaller clumps will give you more control over your forest (especially if you are using the sample color version) and generally look a little bit better (though probably not noticeable on larger maps), whereas the larger clumps can be used to lay down a large forest fast and efficiently.
Tree size should be suitable for most maps, but if you do struggle remember you can always unlock asset scaling in the preferences.
Assets are provided in both custom color and sample color forms.
For custom colors you'll need to set them in the symbols tool before going to trees. The first two colours will colour the canopy, the third colour is the trunk and outline
Play around with the placement rate and density to find what works for you when laying down the trees.