How to keep the model tidy?

I have built a model , yay Image may be NSFW.
Clik here to view..

But its a mess. Difficult to figure what measure is for what . when to use on or the other .

Is it me? 

I would like my model to be self explanatory. So my business users can build reports. 

Any best parctises here ? 

tx,

Gabor