There’s a HUGE difference between “writing every day” and “blogging every day.” I’ve found that writing in a journal every day definitely improves my writing fluidity. However, nobody but me sees my journal. As you correctly point out, writing effective blog posts requires the time and effort necessary for writing, thinking, and revising. Why people seem to think they need to make public everything they write is still a mystery to me. Yes, write every day, but don’t publish everything you write. “Becoming an effective writer” means learning to recognize the difference between what’s worth publishing and what isn’t.