Although you want to get into the spirit of things by giving out beautiful greeting cards, never forget that some holidays aren’t holidays for everyone.
Consider Christmas. While most Americans celebrate this holiday, others don’t for religious, cultural, or personal reasons. For these people, a Christmas greeting card may be considered insensitive. If you can, get to know your customers on a more personal level to avoid such faux pas. You may also want to craft your cards with a neutral theme, both in design and message.
For example, avoid phrases like “Seasons Greetings”, “Merry Christmas”, or anything that directly implies the occasion. Instead, use messages along the lines of “Best Wishes” or “Happy Holidays”. You may also keep the snowy house theme as long as it doesn’t implicitly send an occasion-related message (e.g. a Christmas tree, Christmas lights, etc.).
Better yet, settle for New Year’s greeting cards. At least, everyone welcomes the coming of the new calendar year, even cultures which also honors their own traditional calendars. In general, greeting everyone a Happy New Year at the start of the Gregorian calendar year is a safe practice.
Even better, give greeting cards during your customers’ birthdays. It will give the impression that you went out of your way to greet them on a personally special day.