I prefer to peruse in order. If it is organized as such it is usually done alphabetically from left to right. I can quickly take a complete and accurate inventory. Its pretty simple just and it works for me.
Now,  When I am looking through music or movies at the public library I also use this technique. 
Here's what's up assholes...
To you unorganized people to chose to nut up right up next to me, please, don't be alarmed at me when I reach over and grab the entire selection off the shelf to further inspect ON MY OWN. 
So many of you fucks gasp and gape when I do this but the reality is, you started it.
I was here first.