Signs of Fall ATC
Last year I played around with the idea of leaf line drawings. The basic idea was to put down a layer of paint. (I use acrylic.) Don't try to make it even, basically just slap it down. Then after the paint is dry use the texture of paint to pull out the shapes of leaves. Perhaps the curve of a denser area of paint reminds you of an oak leaf. The more you do it, the more shapes will leap out at you. And even if you don't see anything that calls out to you, the organic texture of the paint is great for giving dimensionality to a simple line drawing.
This year I tried something a little different.
Cardstock, acrylic paint, and Sharpie marker
For this Artist Trading Card, I started off with a fairly thick layer of orange, then a dabbed layer of brown, and finally a top splotchy layer of yellow. Each layer was allowed to dry before starting the next layer. And then after everything was dry I just started drawing with the sharpie. In the past I have worked with pencil first and then gone back over with ink, but I really like the organic feel of just letting the line fall as it will so this time I just went with ink.