...and then move this new layer BELOW the original layer with leaves. To finish, change blend mode of layer with black leaves to Soft light or Screen (whatever looks better). Merge down (Ctrl-E) to combine these 2 layers into one.

Apply the following layer effects:
- Outer glow: blend mode = multiply, color = dark brown, size = 6-7px;
- Inntr glow: blend mode = multiply, color = light brown, size = 20-25px;
- bevel and emboss: style = inner bevel, size = 1, highlight blend mode = color dodge, highlight color = light brown, shadow opacity = 0 (not needed)

Create new layer, and repeat all steps to create more leaves....

... and again, and again!

To make image more interesting, when you finish a layer with leaves, adjust Hue and Lightness (Ctrl-U) slightly, to make leaves more red or darker... or more green and lighter...

..repeat until entire image is filled.