3d trees - question

I have thought several times about creating 3D Australian trees. However, one issue is the leaves. What is an efficient way to depict them so that look realistic? I don't want the tree itself to take weeks to create. 3D Australian trees would look fantastic in TS in my opinion.
I made use of the clear skies today to take some pics of gums, and having looked at them, they may be suitable for 3d design. But I need some tips on how to create them.
I made use of the clear skies today to take some pics of gums, and having looked at them, they may be suitable for 3d design. But I need some tips on how to create them.