Salt experiments and using paper as a brush.
When using salt, you start a process that takes some time and a little bit of planning. The salt melts slowly and need much water and pigments in the process. During the melting process, the surface tension of the water is lowered and will make the pigments move around. This will create beatiful patterns as you have cracked open an amestist or similar stone.
Another way to start a pigment moving process during the drying up in the watercolor paper, is to use thin sheets of glossy paper, like the ones flower bouquets are wrapped with. If you wrinkle the paper before putting it down into the water and pigments, you will get very nice traces.
You can also use a hairdryer to dry up certain pieces of the paper and when that happens, the water in the wet parts will move together with the pigments against the dry ones.