December is here, and you’re ready to start your annual shopathon. You’ve cleared your weekends, put together a gift list and downloaded all your favorite retailers' apps.

But if you haven’t yet worked out how much you can spend on your gift giving, you're not alone: A survey conducted by online loan marketplace LendingTree reveals that 56% of consumers plan to shop without any kind of budget.

The problem, however, with going into the holidays with no spending plan is that you’re potentially jeopardizing your finances.

The fallout for shopping without a budget is typically post-holiday financial regret, which 43% of respondents admitted feeling after last December. Even worse is ringing in the New Year with debt; according to the survey, 27% of holiday shoppers found themselves in the red in early 2016 as a result of last season's spending.

Two out of three shoppers expect to spend up to $500 on holiday gifts this year, the survey also reported. Add the costs for trimmings, travel and last-minute bottles of champagne, and that debt could far surpass just what they spend on presents. (No wonder more than 4% of consumers who overspent last year are still paying it off now, almost a year later!)

One way to avoid feeling financial regret and falling into debt in 2017 is to work out a budget — and a realistic one — before you shop. These tips can help you get that done.

Revisit the impact of last year's spending. Assuming your life hasn’t dramatically changed in a year, you can start building a picture of what you can afford by looking at your past spending.

Take a look at your checking account history and credit card statements from last holiday season. Did you end up going into debt in January that took a few months to pay off, or were you able to pay off your balances in full? Did your holiday spending (including trips, decorations and charitable donations) impede any other important financial goals last year? Assessing the impact of last year's outlay on your overall household budget can help you determine if you need to cut some costs this year.

Brainstorm a near-term savings strategy. If you're finding that what you can spend and what you'd like to spend aren't quite matching up, figure out ways to create cost savings in the next month or two to help make up the difference (the goal here is to not have to accumulate holiday debt). Think of it in terms of trade-offs: Perhaps packing lunch for a week at work will help offset the cost of your spouse's new electronic gadget. Or maybe taking public transportation or carpooling for a while can help offset a plane ticket to see family. The savings may seem small, but they have the potential to add up.

Get a head start on saving for next year's holiday season. If you start setting aside small amounts now, you'll be more prepared for next year's seasonal spending.

Divide next year's desired holiday budget by 12. That's the amount you should start putting away in a special holiday savings account each month, starting in January, so that come next December's shopping season you'll have the cash on hand to cover holiday costs. There will be temptations along the way, but don't give in — focus instead on how good your future holiday will feel if you're debt-free.