Without blogging you may not have taken the time and effort to put your idea into words. And when you did that, you would have realized putting it into words that strangers could understand was not as simple as conceiving the idea was. When conceiving the idea you alone needed to understand. On the other hand the act of putting it in words was quite rewarding and as you fleshed out the idea more as you wrote it down in words for others you were able to think further and build on the idea.
On the other hand as a blogger you want as many great new ideas as you can, to do justice to the depth of your knowledge in your domain of expertise. But the fact is that on some days ideas seem to occur to you and on others they do not. In fact on some days ideas come quick and fast and on other days you face a block and nothing that you do is able to get you started on a new blog post. And here is how you can help yourself by planning well.
Remember the day on which ideas come to you thick and fast. For each idea you will have the option. Either to jot down the basic idea or to do more and flesh out the entire blog post. And the sensible thing to do is to jot down the basic idea in a couple of lines for as many ideas that come on the day when your imagination is particularly fertile. Even if you need to get a blog posting done urgently you should first build up your reserve of fresh great ideas. Once you have got a nice set of ideas all jotted down then you can complete the one blog post that you need to make urgently. And if your creative juices are still flowing you can get back to briefly jotting down more ideas. Even if you do not complete a single blog post all day but capture a lot of ideas you will have used the day well. When I need to write about floor scales I try to first list out ideas for articles on a day when the creative juices are flowing well and then use them when I need them later.
The reason is even on a day when you face a block you will still be able to flesh out an idea you jotted down earlier. And you will be able to write great blog posts without feeling the pressure of coming up with a great new idea each day.