9. Account for Every Dollar

Building off #10, make sure that you've accounted for every dollar you make. That sounds overly meticulous, but it isn't: all it means is that you should "spend" all your money in your budget each month. And that doesn't necessarily mean spending it on stuff—it could mean saving it or putting it toward your 401(k). Some people do better with reverse budgeting, but for most of us, splitting your pay into categories is the best way to make sure it's all accounted for.