Pay yourself first…make sure that you have automatic payments set up to invest in yourself. Ideally, you want this set up going to a low fee index fund. Time and compound interest will be your best friends. The earlier you can start regularly contributing to this fund, the better off you’ll be. The best part about having it automatically set up is that you don’t have to remember to keep investing every month. If you want to invest more, you can. But here, it’s basically like a subscription model (set it and forget it).
If you’re saving up for a specific purchase like a vacation, a new car, a house, etc, set up a separate account and automatically transfer money to that account. Have it set up for every paycheck. If you don’t “see the money” in your regular checking account then you’ll be far less likely to spend it. This will help you actually hit your saving goals and then you won’t have to use credit to purchase your consumer goods.