On these forest bases, I'm going to start by making roots that stick out of the ground slightly. We start with a sheet of ordinary toilet paper:
Cut a piece about 1" x 2" with a pair of sharp scissors. (Make the strip wider for a thicker root.)
Then cut a ½" slit down the middle.
Next, begin twisting the paper tightly to create your root. Start with the forks, and then twist the main root from the other end.
You should end up with something like this: