Always include call-to-actions (CTAs).
Make sure you're asking your audience to take some action, whether it's to love your photo on social media, respond to the comment, share the post, book with you, head to your website, read your blog, or share a photo, etc.
No matter the size of the request, any CTA is great (and is more likely to lead to future, more significant commitments, like booking or purchasing from you).
Don't oversaturate your feed with too many holidays.
It can get overwhelming for your audience and feel spammy or inauthentic. You don't want to use holidays as your excuse to post - strategically select a few to use each month.
Consider what actually applies to your business
For example, if you're a dog walker/pet sitter and don't offer bathing services, you probably don't need to feature Bathing Day. Stick to the ones that really bring up the conversation of what you do, who you serve, and what your message promotes.
Don't just announce the holiday - What's the point of your post?
Don't just say, "Hey, it's Walk Your Dog Day - have fun!"
Promote engagement by starting conversations with your clients. For example, offer trail suggestions for walking their dogs or ask them where their favourite parks are to take their pets.