If you could give us some examples of the style you're currently using, we could probably help more to guide you to something that will fit in your current maps.
When you say "archaic," do you mean similar to historical maps? How old? I am partial to the style of John Speed, who lived in the 16th & 17th century. His map of Scotland, which I have hanging on the wall, shows forested areas as a scattering of small, side-view trees. I can't find a good example on-line with a cursory search, but if you go to the collection at davidrumsey.com, you should be able to find samples of hundreds of historical maps.