Use plain old notebook paper and a binder to create a cheap, but effective journal. Design your own cover to get those creative images jumping around in your head.  Use bright colors, sparkly colors, designs, stick figures, whatever.

Or, better yet, hand your binder and markers over to a child and watch creations flow easily from those small fingertips.  Don't just sit and watch, write about the creator and what he/she creates.  Study  how the colors are carefully chosen, how the fingers move, how the tongue hangs slightly out of the corner of the mouth where a tiny spit bubble has formed. Notice how the colors find their way to fingers, arms, cheeks, and other places, and how there is a pause in the creation of the notebook to concentrate on a new creation--a snazzy, colorful tattoo on the hand or arm, or to paint each fingernail a different color.  You might even experience the delight of a tattoo being meticulously drawn on your hand.  Heck, go all the way and get one on your cheek while you're at it. 

Every time you take this "one-of-a-kind" journal to your favorite chair outside or to a park or to the lake, you're also taking a memory. When you can't think of anything to write about, turn to the cover, study those images again, and remember.