PHOTOSHOP tutorial: painting from reference

This tutorial explains how I do digital paintings in Photoshop, but surely it's not the only way possible. This program offers a lot of possibilities, and what you should do is find your own way to use it
Please tell me if you find any English error, I tried my best not to do them but I'm sure there are... -.- And, if you need to know something more about the process of whatever, don't hesitate to ask, I'm here to answer!

Some notes:
- I used the CS3 Extended version of Photoshop, but the tools are almost the same in the other versions.
- The brush I shown has those features: shape dynamics, dual brush, other dynamics.

Some useful shortcuts (I'm pretty sure that not all of them will work in other Ps versions), they're the ones I use most:
ctrl + t: transform 
ctrl + d: deselect
While using the brush (b):
alt (keep pushing it while using), you'll activate the eyedropper tool.
x, you'll switch the background colour with the main one.
d, reset the default colours in the palette (black as main colour and white as the background one) 
And, as you can suppose, the eraser is e.

Btw, you can find the Thranduil painting here: fav.me/d7te55g