My absolute favorite thing to use is an old debit/credit/gift card. Even the fake ones you get with the junk mail. It's so easy and quick to spread paint around with it! And they are cheap and in most households (like mine) they are plentiful. It's great if you want a thin smear of paint or a thick layer, and it doubles as a mark maker to give you texture! Some people like to use their palette knives for that, which is also a good tool but everyone has their preferences. I prefer to use my palette knife to push paste thru a stencil or to apply it really heavy on a canvas to build up more texture. I like how with a card I can lay down numerous thin layers of paint in my journal and it doesn't require a lot of paint. And it dries fairly quickly so I can keep adding. Here's an example of two completed pages in my journal.
The one on the right was made by swiping down numerous layers of Paper Artsy Fresco Finish paints in bright vivid colors. I then put down the matte black leaving the bright circles behind and journaled around some of the circles with a white gelly pen. I made this page while contemplating my chronic illness.
The page next to it just started out as a place to scrape excess paint off of the palette. It's a good way to get a page jump started and doesn't waste the excess paint that you didn't use! After it had several layers of multiple colors I started adding in other colors using the debit card and took a stencil from Mary Beth Shaw's collection and stenciled in bright red. I really love that stencil!
The page had a graffiti feel to it, which I also love! On a whim I decided to paint a quick portrait of my dog, Cammie, whom we adopted a year and a half ago. I found a photo and just started without any real sense/perspective going on. The results make her look like a Great Dane b/c I got her muzzle too long. She is actually a Pitbull/American Bulldog mix. But I don't care, I liked it anyways and that's what matters. It's my art journal where I make art for myself.
I love how you can still the layers of paint underneath the white, which is exactly what my intent was. Sorry for the shadows on the pictures! The lighting situation wasn't ideal and after trying a dozen different ways I had to give up!