’Tis the season of giving, not only to family and friends, but also to favorite worthy causes. Just as December is make-or-break time for retailers, so it is critical for worthy causes.

Charities can pull in as much as a third of their annual donations this month, according to monitoring organizations such as Charity Navigator and GuideStar (both of which make ratings of national charities available on their websites at no cost). They have pitches featuring sad-eyed animals, sick children and noble veterans, firefighters and others.

It takes care on the part of the giver to assure that a gift will be put to good use.

Ellen Rosenblum, Oregon’s attorney general, also makes giving wisely a bit easier. Each year her office identifies its 20 worst charities, organizations that spend far more on other expenses than they ever give away.

Her 2014 list came out last week. No organization on it is based in Oregon, and not one directs more than 32 percent of what it receives to the folks it purports to help.

That latter is an important marker, by the way. If an institution spends far more to raise money than to help its beneficiaries, you might consider giving somewhere else. It’s so important, in fact, that Rosenblum persuaded lawmakers last year to change state law: Your gifts are no longer tax-deductible from your Oregon income taxes if a charity spends more than 70 percent of what it receives on overhead rather than good works.

Meanwhile, some simple guidelines can help you give wisely.

•Decide what’s important to you. Rather than be swayed by telephone calls or televised pitches, select the causes you wish to support. Do so rationally, rather than in the heat of the moment.

•Check to find out how much of your gift actually supports a charity’s mission. Do expect that some of every gift will go to such things as a charity’s heat, lights and salaries, but be wary if much more than a third is spent that way.

•Many local organizations serve the same groups you hope to help; check with family and friends if you’re unsure about which ones to support. And be careful of giving based on a name — many of those on Rosenblum’s naughty list sound an awful lot like well-known legitimate organizations.

•Finally, don’t give and then forget. Follow a charity’s activities through the year. Does it do what it says it does? If not, look elsewhere in 2015.