Step away from basic photo editing and create your own resources…
The first step for creating this particular brush is taking a picture of a leaf. Find a stock image of a tree, or take your own, and open it up ready.
Choose the Quick Selection tool (Q) and tick the Auto-Enhance box in the Options bar. Set the tool’s Size to 40px and drag an initial selection by clicking and golding the left mouse button over the leaf. This may not select all of the leaf, so control to drag over any remaining parts you want.
There may be parts of the selection that have spilled outside the leaf. To correct this, hold Opt/Alt and click over these parts to remove them. The Quick Selection tool should detect any edges automatically. Brush closely to the edges of the leaf for an accurate selection.
With the leaf selected we can improve this area for an even better cutout. Go to Select>Refine Edge and move the Smooth slider to 100. This reduces any bumps around the edges. Set Feather to 1 and hit OK. The selection won’t appear to be different but the Refine Edge will take effect when the leaf is cut out.
Head to Edit>Define Brush Preset and in the pop-up window, give your new brush a name. A preview will show in this window with a number inside. This indicates the size of the brush in pixels. The larger the number, the bigger the leaf will be.
Close the leaf image without saving, as it’s no longer needed. Open up a tree image and select the Brush tool (B). The leaf brush tip should appear inside the Brush palette (Window>Brush) and here we can set up the brush to make believable-looking leaves on the branches of our tree image.
Inside the Brush palette, set Diameter to 40px and Spacing to 25%. Click on Scattering in the palette and tick Both Axes, set Scatter to 700%, Count to 1 and Count Jitter to 50%. Notice how the preview of the brush changes to reflect the scattering.
Tick the Shape Dynamics box and set Size Jitter to 100% for maximum variation. Set Minimum Diameter to 0% and Angle Jitter to 100%. Set Roundness Jitter to 80% and Minimum Roundness to 30%. Also tick the Flip X Jitter box in this dialog.
The brush can be given dual colours. Hold Opt/Alt to activate the Eyedropper tool and pick a green to use for the other swatch. Tick the Colour Dynamics option in the Brush palette.
Set Foreground/Background Jitter to 100% and Brightness Jitter to 25%. Leave the remaining slider under Colour Dynamics at 0%. Close the Palette now that it’s ready to be used as a leaf brush.
Create a blank layer before painting on the tree. This enables you to erase one or two if they’re slightly out of position. Paint around the branches to scatter leaves across the tree, adjusting the diameter of the brush to help create a sense of depth.