If you are stuck for topics for your content – ask! Who? Your clients, of course. Ask them what they like to read about. Ask them what puzzles them or what they don’t know about things in your industry.
Most people will be more than happy to share their thoughts and brainstorm some subject matter with you so that you can write effectively for your clients.
So, it does require a bit of ‘thinking’ and commitment. But, bearing in mind that Google are now really heavily promoting the creation of content and ranking those who do churn out a prolific amount of relevant content marketing material for their marketing, you really must get going.