A new set of 4 leaf sets found under Decor / Plants, all cost 0.
Use the "Tree without leaves" tree trunk.
The 4 sets of leaves are sitting at 4 different layers enabling you to populate the "Tree without leaves" with leaves. The amount of leaf sets per layer is up to you. They can be rotated and placed off axis to make the tree look wider. The amount of different looking trees is huge. The leaves and tree trunk can be coloured differently. The cheat "moveobjects on" is necessary.