Most of this has already been covered, but here goes:
- Live frugally from the beginning. It's a whole lot easier to live within your means if you never have to make "cut backs". Someone else lives on 80-90% of what you earn. You can too. You just have to be disciplined enough to do it.
- Avoid debt. Avoiding it is easier than getting out of it. This will sometimes mean doing without things, but that's better than paying and paying and paying in the future.
- Save, save, save, save, save. I know I'm being awfully repetative, but if you get used to living on ___% of your salary from the very beginning, it's just easier. Look into direct deposit savings so that it's "automatic".
Start an account for emergency savings, which can never be touched except in an emergency.
Start a short-term savings account for vacations, replacing the roof, buying a bigger TV.
Start retirement savings.
- Buy less house and less car than you can afford. Never borrow what "they" say you can afford -- not unless you want to be strapped every single month to make the maximum payment you can manage. Give yourself some breathing room. Get ahead on your house payment as soon as you can; even $25/month will get it paid off sooner.
- Do not pay attention to people who have more than you. Ignore your friends who are buying big, expensive houses, going on expensive vacations, buying boats, etc. If they're doing these things at a young age, chances are very good that they're doing it on credit. This is counter-productive to long-term financial stability.
- Make it a goal to be debt-free, including your mortgage. It's very freeing to know that what you earn is actually YOURS to keep.
- The most important thing of all: Do what's right NOW. It's awfully easy to say, "We'll pay this back easily in another year or two when we're making more money / when the degree is finished /have recovered from making the downpayment on the house /have paid off our wedding expenses /whatever." In a year or two, when this goal is reached, The truth is that there's never a better time than NOW -- the beginning of their lives together -- to get off to a good start. It's very easy to let 5, 10, 15 years slide by waiting for the perfect time to get out of debt /to start saving for retirement /whatever.