I have two favorite techniques, and it's kind of hard to choose. One is very simple, but the results it produces can be amazing: Pearl Ex powders on black clay. I use texture plates, found objects, molds, all kinds of different things to add texture to sheets of black clay, then add powders to create glowing effects, some that look almost like tie-dye, some that looks sophisticated and chic enough to wear with an evening gown. You can cover flat objects with whole sheets, or cut many sheets into geometric pieces and create a patchwork effect. Imagination is the limit for this one, it's great fun and the effects are amazing.
My other favorite is creating my own variation of faux mokume gane. Gane is a Japanese metalworking technique where sheets of different colored metals are heated together, buckled and sliced into, then smoothed out so that there are ripples, pools, ovals and dots of different colors on the surface of the metal object. Done in polymer clay it can use multiple colors of clays to achieve amazing effects. My variation includes inks, dyes, powders and metal leaf along with translucent clay and creates a glowing effect that is breathtaking and very eyecatching!