• More than any other day, online shopping discounts reach their peak on Fridays, a recent report found.
• Here's how to make the most of the deals while avoiding the pitfalls of "spaving."

Coupons have come a long way from Sunday circulars. And for consumers stretching to make ends meet, they are as indispensable as ever.

Now, with online codes, browser extensions and money-saving apps, there are more ways to find significant discounts at any time — but how good the deals are still depends on the day.

Overall, Friday is the best day for consumers to save money while shopping online, according to a recent study by SimplyCodes. The site assessed coupon release patterns in marketing emails from 30,000 merchants between March and July.

As payday approaches, there is a notable uptick in coupon activity, especially for women's clothing, skin care and alcohol, SimplyCodes found.

Roughly 52% of coupon codes are released between Wednesday and Friday, before the weekend lull, when fewer new coupons are sent out. On Friday alone, the number of coupons released jumps 19%.

Beware of 'spaving'

Whether it's a "limited-time deal" or "buy one, get one free" or simply free shipping, the couponing opportunities are almost overwhelming.

But the lure of a good deal can also lead to excessive buying habits and high-interest credit card debt if you aren't careful, said consumer savings expert Andrea Woroch.

In fact, so-called "spaving," or spending more to save more, is an all-too-common pitfall.

In that case, before you buy, consider whether a deal is really worth it, said Julie Ramhold, a consumer analyst at DealNews.com.

For example, "If you're ordering a few items that are already on sale and you're far from reaching a free shipping threshold, it might be worth using a coupon code to drop the shipping cost to something like $1.99 rather than filling your cart with more items to get 'free' shipping — this way you're still spending less overall," Ramhold said.

"At the same time, if you're stocking up and have a coupon for 25% off your total purchase, it's probably not worth becoming preoccupied with getting free shipping if the overall savings on your items make the shipping costs negligible," she added.

How to make the most of a deal, without spaving

If you are planning a big purchase — or any purchase at all — sign up for a store e-newsletter and mobile alerts, or follow brands and stores on social media to get a coupon for in-store or online savings, Woroch advised.

A price-tracking browser extension such as CamelCamelCamel or Keepa can also help you keep an eye on price changes and alert you when a price drops.

Then, save even more by applying a coupon on top of an already discounted item. "Some stores even let you use more than one coupon on the same order. This could be a coupon for money off, free shipping or a free gift with purchase," Woroch said.

You can search for coupons by store name to find deals quickly using a deal aggregator like CouponCabin.com or RetailMeNot.

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However, it is also important to avoid the temptation to overspend, Woroch cautioned.

If store emails and texts prompt you to shop when you otherwise would not, it may be best to quiet the noise altogether. "Delete shopping apps on your phone that alert you to the latest sale and unsubscribe from store newsletters," she said.

"Instead, look for coupons only when you need them" with a browser plug-in such as SideKick, which scans for applicable codes, Woroch advised.

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