When negotiating for a higher salary, confidence is key. Despite it not being always true, people who are confident in their abilities are typically perceived to be more competent, which will clearly help when asking for a raise. Project your confidence by articulating your words carefully and being mindful of your body language. I've read it from randstad. .randstad.com.sg/career-advice/tips-and-resources/salary-negotiation-is-key-to-a-higher-lifetime-earnings/