The specifics of managing your finances can be complex, but the basic principles of good financial health are simple. Above all else, put your future money toward saving rather than spending.
Personal finance site Wallet Hacks calls this the "prime directive of personal finance", because you can learn a lot from Star Trek. In more verbose terms, the site explains the prime directive like this:
Avoid committing future funds to spending obligations; commit them to saving obligations.
This simple principle governs a ton of financial advice in one boilerplate guideline. Credit cards, for example, force you to put your future paychecks toward spending you've already done. Contributing to your superannuation account puts your future paychecks towards savings. The more you can stick to this guideline, the better off your financial life is.
Of course, as with Star Trek, the prime directive can be bent. Buying a house, for example, commits a lot of your future money toward buying something rather than piling money into a savings account, but you also get something worthwhile for it. If you save your exceptions to the prime directive for the things that really matter, you'll still come out ahead.