~~Hi there Caponata.~~
What type of pottery are you trying to decorate? Has it been glazed? If you have small terracotta pots you can hang them upside down loop and knot a piece of cord through the hole in the bottom and put beads on the cut ends and you have a bell with the bead dongers to ding or dong which ever you like, you can paint with acrylic paints also.
One thing I did was to buy an ordinary terra cotta /clay pot saucer ( cheap as anything) as big or as little as I wanted and went to a ceramic painting place painted a picture on it and had it glazed and I had a wonderful earthy type platter it has to be a bake on glaze to be food safe but if not needed for food you can just use any sealer.
You can decorate dinner sets or glasses or jugs with a proper glass paint, you only need red, green, yellow, black and white to mix and get any colours. You clean with vinegar let dry and paint and then bake in the oven and it is then washable and usable for every day.
It depends on how hard it is for you to get the paints etc.
Let me think some more and I will catch up with you
Oh another one, decorate a pot and glue in a circle of cloth filled with fibre pillow fill ( foam or sand may go in all right too) and you have a pin cushion for your needles for your cross stitching. You know where to find me if I have confused more than helped you.