Many people often ask me about getting into mixed media and deciding what they should buy first.
After thinking about it for a while, I think naturally the first step would be stencils, or masks. They are so versatile and easy to use. You can use a number of media with them, such as modelling paste, like Lori has done below using the Enchantment kit. I always recommend getting started with a light modelling paste that has a consistency of something like heavy whipped cream. That way your pages don't get too wet. Some light modelling pastes are runnier and can warp your paper.
You can also add colour to your modelling paste. I love how Lori used it below.
And then you can also use it with chalk ink and spounce through the stencil, or sponge paint through a stencil, as seen below.
And of course, if you've used a spray ink, you can get twice the use out of the stencil by flipping it over after you have sprayed and placing it somewhere else on your art journal page or layout to get the negative of the pattern.
Why not try out stencils on your layouts in different ways and you'll see what I mean about it being one of the staples of mixed media art journaling or scrapbooking.