Budgets are the foundation of frugal living and personal financial success. Clear and realistic budgets help us better understand our financial picture, rein in irresponsible spending, and develop stronger saving habits. If you’re having a tough time sticking to your budget, maybe it’s not your willpower that’s broken — maybe it’s your budget. Here are seven important budget mistakes you may be making.

1. Not Establishing a Goal

Your budget should be fueled by a crystal clear purpose. Before you make (or remake) your budget, decide exactly what you want to accomplish. Is the goal to get out of credit card debt? To save more aggressively for retirement? To pay off the house five years sooner? Or to simply develop a greater awareness of where your money goes? Having a goal will help you stay on-track and on-budget. (See also: 5 Tricks to Beating Budget Burnout)

2. Skipping Your Retirement Savings

Saving for the future? If it’s not part of your budget, it’s probably not happening. Make sure that your monthly budget includes a healthy contribution to a money market account, IRA, or 401K plan. It’s one the few expenses that will actually pay you back in the long-term.

3. Relying on Inconsistent or Uncertain Income

Funding your budget with tax refunds, year-end bonuses, and other income you’re yet to (and may not) receive, is a bad idea. With one little hiccup, your…