Writing - whether it's every day or once a week - is daunting for people.
"I have nothing to write about" is the common reason.
News Flash: You have more to write about than you think (Slogan shamelessly adapted from Scotiabank...)
The last time I checked, you were an expert in your field.
Your clients probably aren't experts in YOUR field, so pretty much anything you say will be new to them. I'm generalizing, but you get the point. Things that are MUNDANE to you are FRESH to them.
I remember talking with a restauranteur about developments at their business when they mentioned they opened their patio two weekends earlier. "Did you mention it on Facebook or to your customer email list" I asked. "Nope - we never thought of it" was the reply. They missed a golden opportunity to pack their patio by letting their customers know it was open. Why? Because opening the patio wasn't "special" to the restaurant staff or owner.
Take note of "special" things inside your business. Pay attention to industry news that might be relevant to your audience. Make it a habit to write about these things. Once you're used to the habit, you'll find it becomes easier. Probably inside one month.
If you're looking for something that sets you apart from your competition, it'll be the fact that you write and share knowledge all the time. You'll be creating value, building relationships and enhancing trust instead of just spewing advertising.