We all know that it is much more effective to tailor your job applications to each and every job opening. It makes sense because generic applications assume that people didn't care enough to spend some time on the application package. Judge for yourself, whenever you receive a generic marketing letter with some kind of goods offered, do you even take time to read it? Very unlikely. However, if you receive a customized proposal of something you wanted/needed is it going to be of any interest to you? Sure, you would probably read it to find out how you can get and what kind of thing is being offered. In the same employers are looking at job applications...
Learning About the Company
The key thing in customizing your job application (that includes a resume, cover letter, thank you note, and the actual interview) is knowing who you are customizing it for. So let's say you decided to apply for the project manager position at XYZ company. In order to make your job application attractive for hiring authorities, you need to adjust all of your application documents as well as what you say during an interview to the needs and requirements of that very company. But the question is how do I know what the company is all about? What does the company need? What are the company's culture and philosophy? Answers to these questions can provide enough information to deliver an effective job application. You could start with researching online.
In today's world of modern technologies, an online presence for most companies is one of the important attributes. Most businesses have their own websites, some of them even have Facebook, Twitter, and LinkedIn social network accounts. Spending at least an hour or two analyzing the content on those pages could give you an insight into what the company is all about. Learn as much as you can get out of those online resources so that you could also know what to say and how to answer during an interview. If you really want the job you could try and connect with the company's employees. You can hardly get any better information than from people who work for the company. You could either ask the recruiter if you could talk to employees or try and meet one on your own. Knowing what kind of experience those employees have had, what kind of requirements the management puts on them, how different things are done, etc. Having these answers before a formal interview will help you be ready to answer almost any questions successfully.
Right Before the Interview
When you walk into the office of the company where you will have your interview you can have your last chance to look around and learn about the company. If possible, take 3 minutes to observe how people look and how they work. It might be just enough to see how the company invests into people and its facilities. If you are attentive enough those 10-15 minutes before the interview can be more helpful than all of the interview preparations...