My investment strategy (suggestions): get rich slowly (but surely).
(1) to put as much as you can to retirement accounts (mutual funds) to have a long-term investment (also to take the tax advantage);
(2) to buy (big) house(s) to diversify the investments;
(3) to play stocks and ETF funds with some of the left-over money/savings to learn the market movements that will help you to appropriately move the money among different funds in the retirement accounts.