Car shopping is generally guided by online research and pre-selection of your vehicle.
A good rule of thumb is to have a list of no more than THREE cars on your list. Start off by researching reviews on Edmunds, KBB, Cars.com, and other resources found by Google to narrow down your selection based off pros and cons, as well as your taste in equipment, design, and safety ratings.
The next best thing to do is to get out and drives these cars. Make sure to let your salesperson know that you are still shopping and that you have a couple other cars you'd like to test drive.