When you have your two filled shapes, the next step is to create the veins that run through the leaves. Use the Shape Tool to create a series of individual straight lines. Curve the lines as you create them by dragging on the line with the Shape Tool. Press Esc after each line before starting the next line. Extend the ends of the lines a small distance over the edge of the leaf outline.
Change the widths of the veins as shown above.
Select all of the lines then open the Line Gallery (Ctrl F9). Open the Stroke Shapes / Pressure Profiles section. Select the Convex shape and press Apply. If your lines are tapering in the wrong direction, select all the wrong direction lines, switch to the Shape Tool, and press the Reverse Paths icon.
Select all of the tapered lines shown above in red. From the Arrange menu, select Convert Line to Shape. Then Arrange > Combine Shapes > Add Shapes. Repeat this for the tapered lines shown in green.
Apply a solid green fill to each leaf section. We’ll edit the actual colors in the next few steps.
Clone the two shapes. Place the veins over each shape. Select the veins and the shape and Arrange > Combine Shapes > Subtract Shapes (or press Ctrl 2). This removes the vein shapes from the leaf shape.