Wasn't it in Jack & the Beanstalk where the giant sat at a magic table that kept replenishing the food, even as he ate?

As we enter this season of guests, parties, feasts, and gatherings (not to mention the voracious production of freshly baked gifts from our hearths), our penchant for overabundance can really hit us where it hurts--in our bank accounts. And I don't mean overdoing it /indulgence/on the eating side of the equation (that is between you and your maker....or your personal trainer).

I am referring to the purchasing and preparation of the right quantities of food for our festivities. Running out of food is every hostess's nightmare. To avoid that mortification, we often go way too far in the other direction, ending up with three weeks of leftovers after every dinner party. And that private little moment of prayer for forgiveness as we jettison the excess down the disposal.

The tendency to overdo it is a habit developed over many years that needs breaking...easier said than done. Yet, learning to buy only what you need - no more, no less - is good for you emotionally, good for the world and good for your bank account. Here are three practical steps to get you started.

Do the math. Embrace your calculator. People who excel at having "the perfect amount" aren't just good guessers - they take time to do the math. When shopping for a dinner party, they figure out the number of glasses of wine per bottle (four), tally the number of wine drinkers in attendance and estimate the glass per drinker ratio (2.5). At the farmer's market, they know what meals they're planning to cook, for whom, and how much each person will eat. And voila! So many people skip this simple step because it requires us to slow down just the tiniest bit. Take a minute to embrace your calculator and do the math - it may help save you money.

Ask Google, people when in doubt about quantities, take advantage of the fact that the answer is but an internet search away. Seriously, if you're wondering how many pounds of salmon are required to feed 12 hungry diners, the answer lies on the internet. Expert advice made ever-more accessible by the interwebs can be the foil to your over-buying tendencies by providing an outside opinion, additional facts and links to more information.

Create a what NOT to buy list. If you knew you already had 8 cans of chicken stock or three bags of egg noodles, you'd be less likely to buy more, right? Every time you're making a shopping list for a party, also make a list of what you don't need. Stand in front of your fridge and pantry, and write down the staples you already have in stock. This controls your mindless impulse purchases. You can either do this on a case-by-case basis (e.g. holiday dinner, Sunday brunch, etc.) or keep a master list of the things you always buy too much of on your smartphone (the Notes app on an iPhone does the trick).

Sometimes the smartest way to entertain is to remember the old adage: less is more!