1st step
when i want to put color to the main trunk of the tree, i used mesh tool and eyedropper tool
2nd step
for the others branches, the same technique that im used in 2nd step are applied for the this step
* used mesh tool and eyedrooper tool
3rd step
i used brush make the trunk structure
4thfor the leaves..i just used direct selection tool
5th
and then copy it
i put the leave that i make into symbols. double click the Symbol Sprayer Tool in the Toolbox and adjust the settings
6thI usually deselect each time I've released the mouse. i also tweak a bit by using the Symbol Shifter, Cruncher, Sizer, Spinner, Stainer, Screener or Styler Tool.