Here's a practical first step plan: 1) Define your goal and time horizon (e.g., retirement in 20 years or a 5-year goal). 2) Assess your comfort with risk and set a simple target mix (e.g., 60% stocks / 40% bonds if you have a long horizon, adjusting for older age or lower risk tolerance). 3) Start with a simple, diversified, low-cost approach: use a couple of broad-market funds that cover many companies and bonds instead of picking individual stocks. 4) Set up automatic monthly contributions so you invest consistently (start with an affordable amount, such as 200–300 per month or 1–2% of take-home pay, and increase over time). 5) If you have an employer match, contribute enough to capture it. 6) Review and rebalance once a year or when your allocation drifts by about 5–10%. Quick rough math: contributing $300/month for 30 years at ~7% annual return could grow to roughly $360,000–$400,000. 7) Choose a tax-advantaged or tax-friendly account where available to maximize after-tax results.

Tax efficiency means structuring investments so they generate the most after-tax growth possible. This includes using tax-advantaged accounts when possible, holding investments to qualify for long-term tax rates, and managing turnover to minimize taxes from selling investments.