Selling yourself in an interview is exactly the same process that a traditional salesperson goes through to sell anything from cars, property to double glazing, and it is really simple.
Think of a time when you have brought something relatively large. Let’s say a car for example. First of all the sales representative that sold the car to you would have met your expectation of what a reputable person would look like .i.e. Smart attire, polished shoes, groomed etc.
Then they would start to build some rapport, and in turn seemed to like you, so you would have liked them that little bit more.
Almost certainly they will take the time to identify your needs ASAP. Colour, doors, engine, fuel, and find out why you are looking now.
Once armed with all this information you have provided, they like the prosecution in a court of law will use the evidence against you and match your needs to their product.i.e. “Here is a VW Golf. It has X doors, with Y fuel, and in Z colour just like you said you wanted.”
Then the test drive, which is very similar to the interview, at the end the salesperson asks “how did you find the drive?” WHICH IS THE CLOSE!!
You may respond “it’s alright” or “it’s got a nice bit of oomph” which is the same as a client saying he/she likes you and what you have done. The salesperson will close you again and ask you if you will buy the car, which is the same as you asking for the job and seeing if the employer has any objections to giving you the job.
If they do have any objections, you have got to overcome them, ask for clarification that what you have said is acceptable, then close them again. Just like in a sales scenario, this will lead to next steps, put down a deposit, talk of on offer, arrange start date etc.