Drawing the fur on a koala can be a bit tricky, as it is thick, fluffy, and has a distinct texture. One tip is to start with light, sketchy lines to create the basic shape of the fur, and then gradually add more detail as you go. Pay attention to the direction of the fur, which typically grows downwards on a koala's body and upwards on the ears. Use small, short lines to create a fluffy texture, and be sure to vary the length and thickness of the lines to create depth and dimension. You can also use a blending tool, such as a blending stump, to smooth out the lines and create a more realistic look. Practice makes perfect, so don't be afraid to experiment and try out different techniques until you find what works best for you.