Sculpting the Legs
This is going to be fairly image intensive as I'm going to be explaining the finer points of some simple techniques to improve the quality of your GS work.
I used the following to work with the green stuff, a simple GW
style sculpting tool and a small tub of vasalene.
The trick to working with vasalene is to apply it to the flat underside of the rounded end of your sculpting tool by lightly dabbing it in the tub and then wipe it on a spare bit of cloth or rag. Avoid doing this with tissue as fibres may attach to the vasalene, ideally you want a thin greasy film or residue left on the end. You can do the same with water but in my experience this is the best technique to use.
Preparing the Legs.
First off you need a pair of plastic Terminator legs. For the time being I want to keep the tutorial simple enough for everyone to have a bash at regardless of skill level so I'll be making an MK VII style marine.
The first thing that I have done is to base the legs on a standard infantry base, this is more of a personal preference than a rule of thumb. I like big marines but prefer them to be based correctly.
Once that's glued in place and dry I've cut the top of the rounded part that connects to the torso flat in preparation for the torso later int he tutorial. I will be demonstrating how to sculpt the entire torso but don't feel that you need to do that if you're not up to it. You could use a regular marine torso at a pinch if you wanted to but he'll be a bit thinner and not as imposing.
As you can see here I've removed the thigh plates at the top of the legs. This isn't one hundred percent neccesary really but as I'm going to be demonstrationg how to model the thigh armour it suits my needs here. If you want you can just work around them.
The Greaves are the lower half of the legs, the large armoured part of the leg that protects the shins and partially covers the feet.
The key to making the legs is that it's basically filling in the gaps on the terminator legs.
Place a a blob of GS in the centre of the leg like this: