I assume this question is about financial habits that one can practise: Always try to save as much as possible during the early part of your career. And invest, for long term, a large part of it in the stock market (making sure to have diversification and combining dividend stocks with growth stocks).

It has been proven that the stock market provides the best long term returns. Second, spend within your means and pay your credit card bills on time before being charged with hefty interests. If you want to borrow, make sure it is for buying appreciating assets like a house/flat and not to fund depreciating assets like a car.