As I've said, I have very little money-- but tons of time.
Pictured above is the first step of layering putty onto a paperclip armature into the rough form of the body. I decided to leave the arms off for now, as I think it will make sculpting some of the torso detail a little easier.
Since this Troll is a Bloodbowler, I decided he should have some shin pads. Don't know why, but the idea of a Troll in shin pads makes me smile.
To make them, I simply took a couple of small cones of putty and squished them flat with my ruler. Make sure to keep both of the surfaces lubricated so the putty won't stick. I then got a roughly uniform shape with my sculpting tools (right now i'm using bargain dental tools, but I'm going to try making my own soon) and then presses the lines in to represent padding.
Then I just transferred them to the figure. I made some straps and a belt in much the same way, using a roll instead of a cone.
For the shorts, I just flattened out some putty 'discs' as thin as I could and slapped them on. I didn't worry too much about tears and holes, since I figured a troll probably wouldn't bother with a sewing kit for his uniform. The best part was that the putty wrinkled itself in much the same way that real cloth would, and so required very little shaping.