Many tips about investing in stocks and exchange traded funds (ETFs) these days seem to be targeted at the younger investor. But the truth is, it’s never too late to start doing the right thing.

True, the younger you are, the better your position to build wealth and prepare for retirement. But even if you’re in your mid-40s, that doesn’t mean you should write off your portfolio as a lost cause. Young or old, here are some tips from AnnaMaria Andriotis for SmartMoney:

1. Start As Early As You Can. Close to one-third of 30- to 39-year-olds don’t have a 401(k) yet, according to Hewitt Associates. At that age, people should stash at least 10% to 15% of their annual salary in a retirement plan to maintain their lifestyle when it comes time to stop working. But no matter where you are in life, always contribute to your 401(k), and don’t stop.

2. Get All of Your Employer’s Match. Many employers having a matching program, although some have scaled back in the tough economic climate. If your employer has one, use it!

3. Don’t Try to Time the Market. We’ll amend this and say that investors should have a strategy. Why not start practicing when you’re younger? Get in the habit of using your strategy and having a discipline. Even if you’re an older investor, you should implement a strategy and stick to it faithfully. Buy and hold is dead. Investors need to take a more active role in their portfolios these days.

4. Choose Your Risk. One of the most basic investing rules is that the younger you are, the more risk you can afford to take. Assess where you are and what kind of risk you’re comfortable with. By the same token, having a strategy can help you manage your risk by having you in for potential long-term uptrends, while getting you out before a potential long-term downtrend.

5. Put Extra Cash in a Roth. If you’ve got enough going toward your 401(k), stashing your extra cash in a Roth could be to your benefit. The account grows tax-free, and any withdrawals taken during retirement aren’t subject to income tax (if you’re at least 59 1/2) and you’ve held the account for at least five years.

Tags: 401(k), ETF 101, Retirement