At a time when so much of the job search, application, selection and interview process is online and technology-driven, why would anyone consider 'old school' as having any relevance? Isn't your ability to master a 'Tinder for jobs' app sure-fire proof of your suitability for the job?
In most cases, you will do so much of your career progression - from searching to landing your new job - by means of technology. Job search websites & job apps like Zoek, video interviews, online aptitude tests. But in the vast majority of cases, the crux of the process - clinching the deal - will be face to face. And in these situations, adopting old school professionalism will help land that job.
For instance, your first items on the 'be professional' checklist will be pre-interview, and include researching the company, doing a dry run visit before the interview so you know where you're going. Prep your clothes, run the lint roller over the jacket, shine your shoes. On interview day, arrive with plenty of time to spare, and dress appropriately. Having seen a number of candidates turn up less then neatly dressed, you have to wonder what's in their mind when they decide what to wear for an interview, and what is more important to them - their traditional garb, or the job. And lets face it, you are unlikely to be the only candidate - this is an opportunity to give yourself an edge over the other candidates.
Next, go old school on the meet and greet. Firm handshake, smile, and assume nothing about who facing you until you know or sure who is the top dog. Don't interrupt, pause before answering questions, and just generally be polite.A round of handshakes at the conclusion, and your basic people skills have been cemented in the eyes of the interviewer.
Post-interview, do try to send a word of thanks to the interviewer if possible. Even if the interview was arranged via an agency you ought to have been given an email or phone for the people interviewing. A simple note (email or text message) saying how you enjoyed meeting them and how you look forward to meeting them again. Again, do so professionally: don't use short forms of words or abbreviations like you would in a text. And don't however go overboard in trying to contact them.
Overall, aim to show that you can play by the rules, even if you are a rebel at heart.