Our stencils were made using freezer paper and ironing on our stencils. There is a tutorial on line about how to do this here. The only difference was, we used ink for doing screen printing so it'll last longer than acrylic paints.
This one, the rings were wax paper ironed on and then I just painted the rest of the fabric around the rings a teal color. It's a watered down teal.
This is my spider stencil. Loved how this one turned out.
This last one is from placing string and leaves under the fabric and then using a printing roller with paint on it over the top. I don't much care for this method. There may be a better way to do it, but they was we were shown in class it was very hard to control the amount of paint on your roller. I think it looks tacky in places where there was too much ink on the roller.
We did some mono-printing using plexi-glass and the ink paint, but I haven't taken any pictures of those yet. I will try to take some tomorrow and post about those. I enjoyed that process, even though the end result may be unexpected/random from what you painted on the plexi.