If art journaling has no rules, what the heck is it? How can you do something when you don't know what it is? When I started art journaling, I spent a lot of time looking at art journal pages on Flickr and noticed three things going on. This is a generic description but it was a way to get my logical mind wrapped around it.
I'll paint/make backgrounds (i.e. paint, gesso, neocolors, maps, collected papers) ~or~ I'll attach stuff to the page (cut/stitch/glue stuff onto the pages) ~or~ I'll write something (getting words on the page).
PHASE No. 1: Background - Something abstract, perhaps. Maybe paint or a whitewashed page from an old book or map - the backdrop to whatever else you will put on your page.
PHASE No. 2: Ephemera - anything you add to the background - i.e. collage, magazine images, receipts, abstract art, stitching.
PHASE No. 3: Journaling - any words you add intentionally to the page.