Another great way to decorate slab built pieces is called slip trailing. Slip is actually just a slurry of very thin clay. Now this particular bucket of slip is the dregs from my throwing wheel and I save it to use for making slip. If you don't throw and you need some slip you can just take your regular clay, cut it up into some cubes and add some water to it and then you always want to mix your slip to make it nice and smooth. I use a drink mixer like this. You can also do it in a blender. If you really don't have any of that equipment you can also do it by hand it will just take you a really long time to get it smooth and consistent. Give it a nice good mix and once it has gotten pretty smooth and consistent, as you can see it is thick enough that if you touch it it leaves a mound. Then you want to put it into a mustard or ketchup bottle so that you can do slip trailing.