I usually look up which books I want before I go to the book store, and then I make a list to take in with me. I hate going through tons of books looking for something good and ending up disappointed with no book. So usually I do leave with a book or two, unless the ones I want are not in stock.
I also have an ereader now, so I’m not in the bookstore a whole lot anymore. Although I love book stores! I could spend ages in there.