1. BEING TONGUE-TIED IS O.K. 

When I solicited advice from friends on social media, the one overwhelming thing I heard was it’s perfectly acceptable to admit you don’t know what to say. One rabbi said, “Admitting you’re at a loss for words is far more caring and helpful than writing pithy statements like ‘he’s in a better place’ or ‘your child was so perfect, God wanted her to sit beside him.’”

2. SHARE A POSITIVE MEMORY

Instead of falling back on a shopworn phrase, savvy condolers often share a warm or uplifting memory of the deceased.

3. NO COMPARISONS

One bit of quicksand worth avoiding is the temptation to say you know what the other person is going through. Everyone experiences grief differently. While you may have felt angry or overwhelmed when your loved one died, the person you’re writing to may have channeled her grief into work or hyper-efficient house purging.

“The temptation is to bring it back to yourself, but this is not about you,” Ms. Reynolds said. “I heard things like, ‘I was at my friend’s house when I heard,’ ‘I couldn’t sleep all night long,’ ‘I cried so hard.’ Really? Because I think I’m sadder.” A better approach, she said, is to be neutral. “You can absolutely express your sadness and sorrow,” she said, “but remove yourself from the conversation.”

5. GET REAL. 

By contrast, grievers hear so many vacuous phrases that a little straight talk can often be a welcome relief. A little bluntness goes a long way.

The food writer and editor Jane Lear has collected etiquette books for many years and studied how condolence notes have evolved. She prefers the model outlined by Millicent Fenwick in “Vogue’s Book of Etiquette,” published in 1948. First an expression of sympathy (“I was so sorry to hear...”). Second a word about the deceased. Finally an expression of comfort.

Don’t’ be afraid to use the ‘D’ words — dead, died or death. Terms such as ‘expired,’ ‘passed on’ or ‘lost’ are words of denial. ‘Expired’ can be used on a driver’s license but not in person — it’s not respectful.”

7. THERE’S NO TIME LIMIT ON SYMPATHY 

While writing immediately is comforting, it’s not necessary. Many mourners are overwhelmed in the immediate aftermath, and a number told me they especially appreciated cards that arrived weeks or even months after the death.

One friend told me, “I personally back off from doing anything right away and offer to take the griever out for lunch, coffee or dinner a month or so later when everyone has returned to their lives and the person is left alone to deal with the pieces.”

Ms. Reynolds said: “Even three or four months later, touching base can help. I would encourage people to send notes on the deceased’s birthday, on the couple’s anniversary, or some other meaningful occasion.”

Even with these tips, many people may still feel daunted with the pressure to come up with the right words. In that case, send someone else’s words. Mr. Young recommended three poems: “Clearances” by Seamus Heaney, “Funeral Blues” by W. H. Auden or “Infirm” by Gwendolyn Brooks.

Or, do something: Take the deceased’s pet for a walk, run an errand, offer to pick up a relative from the airport.