What are some of the ways to embellish ceramics?

My last test pieces were a series of whorls for drop spindles, they were marbled using glaze, it's the same technique as used on paper. The glazes were 1 part masons powder stain to 2 parts low temperature frit, with two batches, one batch was a water base and the other a mineral turpentine base, both mixed to the consistancy of thick cream. Fill a shallow container with a water base glaze then apply the turps base glaze by pouring or flicking; add pattern by passing a satay stick or similar though the glazes to produce swirls and other pattens. Holding the ceramic piece horizontal in your fingers roll the piece in the top 2-3mm of glaze, it's similar to using a paint roller. The turps base glaze will penetrate the ceramic first and mask the water base glaze which becomes the background, they will not mix! Dry and then bisque, after that apply a clear glaze and fire to finish the piece. The clear can be based on the same low temp frit as used in the marbling glazes, or use a frit appropriate to the temperature you want to fire to. The results are dependant on a random event and so are variable but can be absolutely stunning!

roll out little bits of clay and use slip to attach the design to the piece. cut out designs with a cookie cutter and attach pieces. buy a small extruder (all the hobby and craft stores have them where they sell clay for about $8-10, complete with all kinds of little design attachments)

go to the library and look at ceramics books. You will see all sorts of designs where artists have added clay to the thrown pieces. Also, use a pencil or tool to carve into the piece.. If you take the time to read any beginner ceramics books, y ou will see how to do this...

You can buy lava rocks, but I've never noticed much difference in the taste. Try putting a few wood chips in an empty tin can and setting that inside the grill. But read your manual first. Some specifically say don't do it.