I can't say I begin to even know, but I've been told that I'm not "really" a girl. (I say what I mean, and I want you to do the same) So when I stumbled upon this topic I figured it was a perfect topic for me to pull my junk out and discuss.
Masturbation is different for everybody... or at least it is when you're a girl. Some girls like more clit stimulation and some will kick you through a wall if you hit their clit or if you just spend too much time there. From my experience the basics don't change from guy to guy. There's a "sweet spot" for jerking it, but as far as their mind... that's where I think I'm the same as the guys.
When I'm masturbating whether I'm using a toy or just my fingers I'm either following along with the porn or if nothing is on the TV I'm making my own in my head.
I don't imagine a guys thought pattern to be much different. He's thinking about something that is going to help him get there.