It's sound simplistic, but many people struggled with basic rule.
Make sure you know what your job is worth in the marketplace, by conducting an evaluation of your skils, productivity, job task, contribution of the company, and the going rate, both inside and outside the company, for what you do. Being underpaid even a thousand dollars a year can have a significant cumulative effect over the course of your working life. No matter how much or how little you're paid, you'll never get ahead if you spend more than you earn. Often it's easier to spend less than it is to earn more, and a little cost-cutting effort in a number of areas can result in big savings. it doesn't have to involve making big sacrifice.