Here's one technique I am starting to use. You can make a pot from one clay, but why stop there? The world over, people have invented ways to mix clays to produce a patterned clay to pot with. It can be very complicated; you can combine thin, cut slabs of clay of various colors to make pictures that go through a roll of clay, seen when the roll is cut into slices. No way do I want to learn that.
You can stack thin slabs of different colored clays (2 or 3, don't overdo it), throw them hard onto the table to connect and thin them, cut vertically, restack, repeat until done. Then the stacks are sliced and pieces arranged to make patterns, either as a surface over other clay or as the structure of a pot.
It can also be very simple: casually cut slabs of 2 or 3 clays, and wedge (that's knead) them partly together. As you shape a pot on the wheel, the clays combine further and swirl. That's for me.
In English, especially in Britain, this is agate clay, an imitation of agate stone. In Japan, it is nerikome or neriage (the difference between them evidently is the way the pot is made.)
Yes, you have to use clays with similar shrinkage and the same firing temperature, to be sure the pot holds together. Yes, you need a lot of contrast among the colors; two differently colored stonewares will do it, or a clay in sections colored differently by wedging in stains or oxides. Yes, the pot does take a lot of trimming, scraping, sanding to show the clay swirl clearly. And different amounts of wedging the colors together produce quite different results.
This comes from combining the clays less. I think I like it better with a tighter swirl. And without glaze, like the bottom of this vase.
Even the simplest version of this technique involves complications and alternatives. It's all wonderfully endless.
