As much as you can afford to. The best strategy is to look at your monthly income and expenses and figure out how much you can invest monthly. Consistent monthly investment into a balanced portfolio will make you incredibly wealthy if you stick with it for the long run. Even if you can only invest $50 or $100 a month to start, start with that. It’s not about putting crazy amounts of money away. It’s more about building the habit and creating a strong financial foundation for yourself.