First off, reference photo: http://imagizer.imageshack.us/a/img924/5369/loX3hQ.jpg
Next, got all the items for the pose positioned on more-or-less the right spot and layer.
Then cleaned up the pose by masking onto insignia shapes and adjusting position/layer where needed.
Gave him a base skin color, hid the masking shapes, cleaned up linework I didn’t like by hiding it behind solid-colored insignia shapes, and added a little detailing here and there.
Added tattoos, shorts, hair, and accessories, mostly by masking directly onto the body pieces. But a few were just placed over or masked onto insignia shapes again.
Filled in the rest of the elements with their base color schemes and once again cleaned up the image by hiding the insignias used for masking.
Highlighted/shaded with gradient background items.
Threw up a simple background n called it good!