1. Beginning
First of all open a template or make a new document, how about for this tutorial you just make a new document and fill the background with a dark grey.
For the leaves I used this picture as a guide.
I got the image off of google, sure the quality looks absolute bogus, but the shape is still there.
So drag the picture into your canvas like so:
2. Layer Styles
With the Polygonal Lasso Tool (L)
make a selection all around the leaves, you don't have to include the stem but i did to begin with.
Fill the selection with a dark green, I used #748004.
Apply the following Layer Styles to the leaves layer:
Get the pattern from here
3. Dodge & Burn
Use the Dodge and Burn Tools to make some highlights and shadows on the leaves, it doesn't have to be at all perfect.
Dodge Tool:
Burn Tool:
4. Duplicating and Resizing
Duplicate the main leaves layer and flip it horizontally ( Edit > Transform > Flip Horizontal )
Press CTRL+T to go into Transform Mode, and resize the shape to 50%.
Move the smaller leaves to around the top left of the big set of leaves and erase the stem.
Duplicate the smaller set of leaves, flip it horizontally again and move it underneath the main layer and set of leaves.
Duplicate a smaller set again and move it over to the right area.
5. Merging and Finishing
Merge all of the leaf layers together. Before you merge them together you can put them into a group and duplicate them if you want.
After you've merged them, resize the leaves to about 20% in width and height.
Apply Filter > Sharpen > Sharpen once and fade it to about 20% since it will be too strong.
To finish it off I erased the stem, added another with the stem under it and added it to a basic clan-styled content box.
That's it for this tutorial, you can download the PSD from here if you want.
More Tutorials: 
