We take courses in school on algebra, history, and art, but where’s the class on personal finances?

The fact that only 32% of Americans have a household budget likely means most people don’t know how to create one.

Having a budget helps you stay in line with your expenses and avoid credit card debt. Here are some things to avoid when first creating your budget for household expenses.

1. Using a Spreadsheet

Maybe you did learn how to make a rudimentary budget in high school back in 2000 and Excel was your platform. While spreadsheets are great for some things, budgeting is no longer one of them. Unless you’re one of the few who actually loves spreadsheets, and you stay disciplined with using them for your budget.

If you’re not a spreadsheet nazi, there are budgeting tools like Mint and EveryDollar. These are more effective than spreadsheets in that they offer more robust features to help you stay on track for saving money and paying off debt. Both of these budgeting tools let you categorize expenses so you can see where your money is going, and they let you set goals for saving, which can come in handy if you’re trying to buy a house or pay off debt.

2. Not Assigning All Categories

So you’ve got rent, groceries, and other bills in your budget… but what about your monthly Netflix subscription or your weekly beer-with-the-gang expense? Ignoring expenses is the first way to blow your budget, so make sure you include any and all expenses.

Creating a category for entertainment, for example, ensures that you plan for those weekly outings… or realize you can’t actually afford them.

It’s typically the indulgences that get overlooked, like smoking and drinking. People often don’t want to add them to their budget, because they pretend like they don’t exist. If you’re going to indulge, you have to be honest with your budget.

3. Not Having a Buffer

It happens to everyone: some months you’ll go over budget in one category or another.

Maybe this month your license plate renewal is due, blowing your auto budget. But if you have a buffer built into your budget, say $200, you won’t have to worry if a category is exceeded one month.

You can keep the buffer in your checking account. Just remember if you set your buffer to $200, then $200 is your new zero-sum.

4. Keeping Business and Personal Expenses in One Account

If you have a small business, make sure you have a separate checking account for business expenses. Keeping business and personal expenses together only complicates the budget and your finances, and you’ll need them separate for filing your taxes in April.

There are tools for managing your business accounts, too, so look into something like FreshBooks to ensure that you’re tracking business expenses and keeping them separate from your personal budget.

5. Not Budgeting Credit Card Debt

Credit cards are tricky. While they allow you to make purchases now, even if you don’t have the money to pay for the item, it’s all too easy to rack up massive debt if you don’t pay off your cards promptly. There are positives and negatives to credit cards, but if you’re responsible with them you’ll be fine.

Make sure you include a monthly budget for paying off or paying down credit card debt. It’s always best to pay your credit cards off in full each month, but if you’ve racked up some credit card debt, work a system into your budget to pay it off.

The Debt Snowball or Debt Avalanche both work well. Choose what’s best for you.

6. Forgetting to Budget Savings

You’ve thought of all your monthly expenses, and you’re pleased to see you’ll have a little extra left at the end of each month. But wait! You haven’t accounted for saving money, either for a rainy day, something you want to buy (like a house or a car), or retirement (or all of the above).

It’s not sexy, but saving money is the best way to ensure that you don’t have to worry in the future about your finances. Even if you can only save $100 a month, budget for it, and then put that money in an interest-bearing savings account.

Be diligent in updating your budget and tracking your expenses. If you’ve maxed out a category, stop spending in it. For example: if it’s the 20th of the month and your grocery budget is maxed out, scrounge around your pantry and eat what’s on hand rather than going over on the budget.

You’d be amazed how possible it is to not spend any money if necessary. Even for 30 days.