An art journal should be a safe place to explore feelings, ideas, art techniques, educations, your belly button and everything else in your life. In your art journal you should be free and feel free to do that. If you are focusing on the end product you lose the point of keeping an art journal and that is to explore all thatI listed above. What the page looks like at the end doesn't matter as much as getting it to that point and HOW you got to that point. Don't approach the page thinking of how it's going to look at the end. Start working on the page without thought.
Do What feels right.
Do what feels wrong.
Try new things in your art journal. No one else needs to see it, unless you want them to. Be happy. Be sad. Angry. Melancholic. drunk. Introspective. Think about yourself. Your family. The world. Politics. Mass Media. Hysteria. Your friends. People you don't know. Think it out. Write it down. Draw it. Paint it. Doodle. Scribble. Wax. INk Stamp Charcoal. Scrub. Brush. Sand Emboss.