The short answer
If you want one line that works for nearly anyone, write "Merry Christmas and Happy New Year" and then add a single sentence that only fits that person. The first part does the polite work. The second part is why the card gets kept. If the recipient does not celebrate Christmas, "Happy Holidays" or "Wishing you a warm season" covers the same ground with no awkwardness.
I look for two things in a card: a greeting that matches the card's artwork, and one detail that proves a human wrote it. Get those right and the rest sorts itself out.
Greetings that work for almost anyone
These are the workhorses. They fit a neighbor, a dentist, a teacher, a cousin you see twice a decade.
- Merry Christmas and Happy New Year
- Wishing you a joyful holiday season
- Happy Holidays from our house to yours
- Warmest wishes this Christmas
- Hope your holidays bring good food and better company
None of these are clever. That is the point. A plain greeting never lands wrong, and it leaves room for the sentence you actually want to write underneath.
Match the wording to the recipient
Family you are close to
Skip the formality. Mention something from the year, even something small: a trip, a new job, a dog, a move. "Merry Christmas, and I still owe you a rematch at the table" beats any printed verse. Nicknames are fine here. Full names are not.
Friends you actually talk to
Reference a shared joke or the last time you saw them. "Merry Christmas. Next year we finally take that trip." Short, specific, warm.
Colleagues, clients, and people you barely know
Keep it neutral and skip the personal details. "Wishing you and your family a happy holiday season" is plenty. Do not write anything that could be read as a joke, a hint, or a comment on someone's year. If the person reports to you, or you report to them, leave out anything about their work.
Faith-based cards
If the card has a nativity scene or a printed verse, the greeting should agree with it. "May the peace of Christ be with you this Christmas" fits. Writing "Season's Greetings" under a Bible verse reads like two cards glued together.
Someone who has had a hard year
Acknowledge it, then keep the card light. "Thinking of you this Christmas" is honest and does not demand a reply. Avoid the phrase "this is your best year yet" unless you know it is true.
How much should you write?
One to three sentences is the sweet spot for a personal card. Under that, it feels like a signature on a form letter. Over that, and you have written a letter, which deserves its own envelope and its own mailing date.
How to sign off
Closings get people stuck more than the greeting does. "Love" for family and close friends. "Warm wishes," "Best," or "With love from our family to yours" for everyone else. Add the names of everyone in the household, including children, since half the fun of a card is seeing who signed it.
Timing and the practical bits
Cards land best in the two weeks before Christmas, so aim to mail domestic ones by the middle of December. The postal service publishes holiday deadlines each year, and they shift, so check before you buy stamps in bulk. Print addresses clearly, spell names correctly, and put a return address on the back. Small things, but they decide whether the card arrives or turns into a mystery.