I used a myriad of different things as the page base: newspaper ads, scrapbook paper scraps, old book pages, napkins. And they're not neatly cut, either! It's a junk journal so the more ragged, imperfect & chunky - the better!
I've filled it with some personal items like pictures, momentos like event tickets or personal cards. I've made flaps that hide little things underneath or there are envelopes of varying sizes throughout that have little goodies inside. Washi tape, Tim Holtz paper dolls,, small clothes pins to clip things in place, different types of embellishments, random ephemera - and so much more.
No neat edges or perfectly aligned pages - you just grabbed your photos & momentos, got out some tape or paste, an old pair of scissors, & went to town!
After all - isn't that why we love looking through them - the imperfections yet the heart-felt message conveyed?!