Introduction
The idea for the image came from a short scene in one of my favourite movies, "Pulp Fiction”. In this particular scene, we see actor "Bruce Willis” playing the character of a boxer named "Butch”, as he wakes up in a boxing dressing room after having a little nightmare just minutes before a big fight (Fig.01). Obviously, I didn't try to remake the exact scene, it was just inspirational for me.

Fig. 01
Searching for references
I started with the search for good reference images for lockers and dressings rooms (sports related) (Fig.02).

Fig. 02
Then I searched for other references, such as props, boxers' clothing, rats, and basically everything that I wanted to appear in the final image (Fig.03-04).

Fig. 03

Fig. 04
A few places for great references are: www.imagebank.com, www.dreamstime.com, www.photo.net, www.google.com, and www.morguefile.com.
Modelling
In this part I'm going to explain some of the methods I've used to model the environment. I'm not going to talk about the character modeling, there's a lot of excellent tutorials on the web and on 3dtotals website about character modeling, check them out.
Modelling the room
I started with a spline; drawing - from the top view - the actual plan of the room's walls (Fig.05).

Fig. 05
Then I used outline to determine the initial thickness (Fig.06).

Fig. 06
With editable spline vertex sub object, I changed the thickness (Fig.07).

Fig. 07