I very rarely pay any attention to how the book looks... mostly because they're turned to the side at the store
I do follow somewhat of a routine (unless looking for a specific book). I'll usually notice the title and then will check 1 or 2 things right away. First, the copyright date to determine if it's recent enough that the material will still be relevant. If that's good, then I check the TOC. So long as both meet my expectations I'll flip through some of it to get an idea of how the info is presented. If I like it, I buy it
