By now, you should have a good idea of what you're spending in the grocery store each week. You've probably been tracking your money on a piece of paper, if you've followed my "homework assignment" from the first week.

But if you're household is anything like mine, you've got more on your mind than money. It's time to move beyond paper lists and finding a simple, long-term solution to your grocery budget. The easier it is to stay on track, the more likely you are to follow a budget.

Whether you plan to trim spending or just keep your grocery bill from growing, the following tips will help you stay on track each week.

Cash or gift cards

Cash is the easiest and most popular way to budget. If you plan to spend $50 on food this week (insert your family's grocery budget here), put $50 in your wallet or in an envelope on the refrigerator. When that money's gone, it's time to stop spending. This also works well if you budget for groceries and takeout as one lump sum.

It takes discipline to place just $50 worth of groceries in your cart. Keep a running tally of costs as you work through your shopping list, or use a calculator to ensure that you'll have enough money at checkout. (You did remember the shopping list, right?) Don't feel self-conscious: If you look carefully, you may notice that lots of people are doing this now. I round each item to the nearest 50 cents to simplify the math.

If you're not comfortable carrying cash or spend cash too quickly, consider gift cards. You can purchase store gift cards at most stores and use these cards to pay for your groceries each week. Keep in mind that like cash, gift cards cannot be replaced if they are stolen.

Credit and debit

There are lots of reasons to use a debit or credit card at the grocery store. You may earn rewards points or money back from a credit or debit card. And if your card is lost or stolen, you aren't responsible for any fraudulent charges.

It's much easier to spend more with a credit or debit card, so you should still be aware of how much money you're spending as you place items in the cart. You won't have the fear of not having enough cash as a motive! Set a spending limit and stick to it.

I personally use a credit card for my grocery shopping because we have a great "money back" rewards system. If you pay your bill in full each month and aren't being charged any interest or fees, there's nothing wrong with using a credit or debit card.

Staying flexible

Will you spend $50 a week, $100 per paycheck, or $200 each month? It works out to the same amount, but how you think about money may change your shopping habits.

I find it easiest to budget by the month. If there's a great sale one week, I can stock up on our family's favorite foods without worrying about going over budget. I simply adjust our spending for the rest of the month to make up for that great sale. Doing this allows us to take advantage of low prices, instead of buying the same thing each week regardless of its price. Sales tend to run in eight-12 week cycles. If you stock up on several weeks worth of favorite items like snack foods or pantry staples, you'll never need to pay full price. Why pay more for an item than you have to?

Whether you budget with cash or a credit card, remaining flexible will be important as you strive to lower your grocery bill. Keep checking those sales, and watch your grocery bill continue to drop!