To make a good custom minifigure sometimes simple is better, take for example these A.P.E.X Custom Minifigures by Titolian.
A militarist group that goes by the name APEX, these expertly trained soldiers are as mysterious as they are unpredicatable. Striking with devastating force, then disappearing without a trace, APEX has become one of the most infamous and feared organizations on the planet. Their reputation stems from the questions that surround them. Who founded this group? Who leads it? More importantly, who funds it and how do they have access to advanced technology being developed in secrecy by varying governments? These questions may never be answered, but APEX lives on, giving armies around the world cause to fear.
Excerpt from a news article detailing APEX(Accurate Precise EXact) rise to power.
The chrome helmets really stand-out, especially the blue ones and the torso/leg combinations as a whole are pretty good. Reversing the Stormtrooper torso and adding arms that match the leg colour shows some great imagination!