It’s that time of year when plenty of couples are either getting engaged or shopping for rings.

Nearly 40 percent of engagements happen between November and February, with December being the most popular month, according to WeddingWire.com. (The No. 1 day for proposing is Christmas, then Valentine’s Day.)

If you are still shopping around, you know rings can be pricey. The average ring costs about $5,000, according to WeddingWire.com.

For a savvy shopper, learning about the features that drive up the cost of an engagement ring can lead to big savings. Many of these details aren’t even visible to the naked eye beyond a certain point, jewelers say. Here are some smart steps you can take to help make a ring fit your budget:

1. Skimp on a fraction of a carat

Jewelers will price diamonds partly on how many carats they weigh, with each full carat adding significantly to the value. But buying a diamond that is just shy of that critical weight – think a ring that is 1.8 carats instead of 2 carats – can save you money. “There could be a pretty significant change in the cost,” says Jerry Ehrenwald, president and chief executive of the International Gemological Institute, which certifies diamonds. Take two diamonds that are identical in terms of color and clarity. Buying a 0.9 carat diamond instead of a 1 carat diamond can bring the price down by 20 to 25 percent, says Anubh Shah, chief executive and founder of Four Mine jewelry.

2. Sacrifice on clarity

The top grade in terms of clarity when evaluating a diamond is flawless, followed by internally flawless, meaning that there are no imperfections visible under 10 power magnification, Ehrenwald says. Couples can actually go down multiple grades in clarity before the cloudiness becomes visible to the average person, he says. The following levels are: very very slightly included (VVS1 and VVS2), very slightly included (VS1 and VS2), slightly included (SI1 and SI2) and included (I1, I2 and I3). Shoppers looking to save can go all the way down to the VS1 and VS2 level before any imperfections will be noticeable to the naked eye, he says.

3. Buy gold instead of platinum

Raw platinum isn’t that much more expensive than gold, but when it comes to jewelry, consumers buying gold have more options, Shah says. That’s because gold can be purchased either in 18 karat or 14 karat, giving consumers a more affordable choice (a karat is a measure of purity of gold). For a classic ring setting that includes some diamond accents, using 14k white gold instead of 18k gold can reduce the price by up to 20 percent, Shah estimates. While the latter 18k gold is more pure, it isn’t much more durable or beautiful than 14k, he says.

4. Go custom

Engagement rings, like a lot of other things, can be cheaper if you order them online. The reason why is pretty straightforward: Going online gives shoppers more options to choose from and to comparison shop, Shah says. People may also find more choices for customizing their order and bringing the price down.

5. Go with a nontraditional stone

It’s becoming more common to go beyond the diamond when it comes to engagement rings, says Kim Forrest, editor of WeddingWire.com. (Remember Kate Middleton’s sapphire engagement ring?) Rubies, sapphires and emeralds are all being used more regularly now, Forrest says. These stones can be more affordable for some couples, though not always. “A very high-quality colored stone can sometimes cost more than a low-quality diamond,” she says.