This might be a little bit inception-y, to post a free blog planner printable in a blog post, but I love a bit of sci-fi so here we go!
I've been using this planner that I quickly threw together to keep me up to date and keep a proper schedule on when and what to post. I find it a bit difficult to write spontaneously, I like to know what I'm aiming for. My university essays used to be 12 page plans of references and bullet points before I got to stringing a full sentence together.
You can print it off on A4 sheets which I do, and I find there's plenty of room to fill in everything I need to know. If you want to chop and change it to a different size, feel free! There's a space to plan out the main content, one for a list of need to do's, one for any images you need to source/take/scour through your entire computer for.
So there you go! Save, print, use. Go forth and be organised.