Pick the card by relationship and tone first, then do the real work inside. A cheap card with a specific memory written in it beats a letterpress blank where you only sign your name. Most people read the message, not the paper stock.
Match tone to the relationship
Funny works for friends, siblings, and anyone you already trade jokes with. Sentimental lands better with parents, grandparents, and partners, where a short sincere note does not read as a joke that missed. For coworkers and casual acquaintances, aim for warm and light. Inside jokes nobody else understands get awkward when the card is passed around an office.
What to write inside
Specific beats poetic. Two or three sentences is plenty.
- One concrete memory from the past year, named in a few words.
- One thing you notice about them that they may not notice in themselves.
- One small, real wish instead of a generic best-year-ever line.
If you are stuck, start with “I still think about” and finish the sentence. That gets you past the blank page faster than hunting for the perfect verse.
Size, weight, and postage
Standard folded cards, about 4.25 by 5.5 inches, fit letter-size rules when the envelope is rectangular. One card plus envelope sits under an ounce, so a single first-class stamp covers it. Two things push you into extra postage: square envelopes, and anything rigid, thick, or bumpy, such as a card with a button, a wooden token, or a fat ribbon. The USPS treats those as nonmachinable and charges more. If the card is a keepsake, hand-deliver it or ask for hand cancelling at the counter.
Store-bought or handmade
Handmade gets remembered when the person values effort and time. Store-bought wins when the design or the humor is exactly right and you would otherwise spend three evenings on something crooked. There is no prize for either. A printed card with a handwritten paragraph is the safest middle ground.
Kids, milestones, and group cards
For young kids the envelope and the stickers get more attention than the words, so keep the message short and readable. Milestone birthdays invite humor, but check who else will see the card before you commit to the joke. A group card works best when each person writes one line and signs, rather than one long message with twelve signatures crammed at the bottom.
Timing
First-class mail takes a few business days across the country, so drop the card in the mail at least a week ahead if the date matters. If you are already past the deadline, a phone call plus a card that arrives late beats silence. Nobody has ever been upset about a birthday card that showed up on the Tuesday after.
The bottom line
Choose for the person, write something only you could write, and check the envelope before you seal it. The card is just the delivery method for the message.