I typed this up earlier only to hit the back button and lost everything. Oh well, second time's the charm!
They don't look very Christmasy, but that is why I chose them. Out of all the trees they had, they looked the most generic, letting them be used in more settings. The way they are flocked gives them a very high quality look that I haven't seen with other trees.
The only problem, though, is that the bases are not brown like in the last photo. They are actually white, to simulate fallen snow. What I do is just take an earth color, and paint it over the base. Then I just finish with a black ink wash to darken it a little and make it more realistic.
Sometimes the bases are loosely attached with the cheap glue used in assembly. What I do in this case is just to lightly twist the tree off the base, scrape away the glue, and run super glue into the tree's pin before slotting it back into the base. This only needs to be done to the looser bases; most are attached just fine and don't require this.
So you have finished trees, but you need a base. I just get a dark green piece of felt and cut it into an interesting natural shape, and then set the trees on top. The felt base may stand out on the battlemat a little, but the contrast ensures that the borders of the forest are clearly defined, and when you place the modified trees onto them, they look great.
Here are some pictures of the trees/forests used in games:
Anyway, there's that. Christmas is a long way off, but you can just use the felt until then. Next time I will show how to make defenses such as barbed wire, Rommel's Asparagus, hedgehogs, and Dragon's Teeth!