maybe you can use obelisks, but I've never thought that was possible...I Wish bungie would make trees as items...
Honestly, depending on size, you can use different techniques. The general consensus is this, though: Place trunk object or multiple interlocked trunk objects, (if necessary) make branch objects, interlock or otherwise place upside-down tin cups as leaves/branches.
Try using thin wooden bridges to capture the tree look as vest as we can. If the tree is gigantic, you can use wood bridges and tin cups for leaves. An alternative would be to use columns.
wooden bridge for the trunk, coluns for the brances and sender nodes for the leaves. I find that works best for me.
What about sing a column for the trunk, and then reciever nodes as foliage. about three or four teleporters should work.