For me, I know I love everything new age...so I always head for that section first to see if there is something interesting. If I dont, then I try something else...i also look at the title & check the back to see if it gets me hype...if not, then i choose something else...
Its always good to know what interests you as in a particular subject! If not always look for other things that interest you...that is what I do!
If I walk into a library I usually look for the books that look slightly more worn, they have a nicer feel to them, plus I know other people have also read them which means that it couldn't have been that bad. Then after that I look at the cover and read the back page to see what it is about and whether I would like it.
A lot of times the title and the cover appeals to me first. But then I always read the back to see if it interests me. Of course don't judge a book by it's cover. Some of the most amazing books have ugly covers.
I always choose my age group and then read the Back page of the book,if it is in my interest and I know I am investing in something that I would enjoy or it will help me,I go select it.
It's also good to know what genre you prefer.
I agree 100% :)