"I try to smooth as much as possible before I bake my pieces so that sanding is often only done to achieve a polished finish. I use wet/dry paper. 250 grit 400 grit and 600 grit. Anything more coarse the 250 is really going to cause more marks on clay then it will remove. I usually sand over the sink and rinse the piece and the paper frequently. I don't sand until the piece fully cured. With wet sanding it is more about repetitive rubbing then pushing.
To get into small areas I take a small piece of paper and fold it over so the paper sides are together then roll it so it has a point at one end like a pencil. when I am done sanding I use a soft cotton square and rinse the entire piece and once the piece is completely dry (10minutes). I use acetone to remove the remaining almost invisible lines and to restore a uniform color to the entire surface. I use q-tips.
Don't be afraid to waste them. You don't want the acetone on your skin. I dries you out badly. Gently rub and wipe the surface. Do not use a dippy amount you want to wipe not wet. Too much acetone will turn it white. Damp not wet q-tip do the best. " Source: http://www.ooakdollart.com/forums/viewtopic.php?f=19&t=5579
Smoothing Your Sculpture (baby oil)
You want to smooth everything out and blend everything as best you can before baking.
I have see many Artists use baby oil both before and after baking;
Used Before Baking: It can be used to smooth out the fingerprints and other imperfections on the surface of your sculpt and you want to use a very small amount.
Used After Baking: I've seen it used when you bake your piece and there are maybe a small amount of imperfections that can be scraped off with an x-acto blade and the oil is used to get rid of the scrape marks, again used in very small amounts.
Curing Your Sculpture
Make sure you bake / cure your piece to the manufacturer's recommendations to ensure your sculpture cures / hardens completely thereby ensuring it's longevity.
Preventing Stress Cracks
If you notice your sculpture gets random cracks after its cooled and wonder why, its more than likely that you didn't cool it properly. And yes, there's a right way to do it. After you cure your piece, and after every cure after that, make sure you leave it alone; don't uncover it, don't remove the cover to the convection over or open the oven door. Leave everything as it is. Let it cool completely on it's own. It might take an hour or so but let it happen. preventing these cracks is so worth it.
Blushing Your Sculpture
When blushing / painting, less is more is a good rule of thumb to go by as it's easier and better to keep adding paint until satisfied then to have to remove any.
Having A Clean Sculpture
Wash your hands regularly, about every 20mins or so, to prevent lint getting onto your clay. You can also wear vinyl gloves to prevent lint on your clay. I also recently found out that you can use alcohol swabs. They work for smoothing the clay and removing dirt. You work for a while, wipe down with an alcohol pad, work some more, wipe again, etc. They dry almost immediately and the alcohol does not harm the surface of the clay. You can also use rubbing alcohol on a clean soft cloth too.
