I suggest that you have a stack of tags ready to use while doing this technique. There is always paint left on the mat when you're done with the first tag and although we all seem to have enough supplies to last a life time we never like to waste.
#1 on the far left - place the tag straight down on the paint walking your fingers around the tag and then lift straight up. You can see how the colors are smooshed (technical term).
#2 in the center - place the tag straight down on the paint, walk your fingers around, then pull downward (just a little) and lift straight up. You can see how the colors move together.
#3 on the far right -place the tag straight down on the paint, walk your fingers around and pull downward a little more than in example 2 and lift straight up. More of a marble effect.
#4 shown above - (my personal favorite) I took sample #3 from above while it was still wet - spritzed it with lots of water. The spritzing makes the paint move around and some even runs off the tag. The colors are still separate but much more subtle. The thing I love about these paints is that they never become muddy. The colors blend but hold true to their original color.
If you like more movement in your paint, you can always swipe it through the paint or even twist it before you pick it up. If you don't get complete coverage with the first application, simply put the tag back in the paint.
#5 This tag was placed on the paint and then twisted before lifting
#6 This tag was placed next to the paint and then pulled through it.
You are never going to get the same results twice - so "embrace imperfection" and go for it. By the time you add Distress Ink and maybe some water splats, you'll be happy with your tag.
Another thing to remember is that once the paint has dried, it is there to stay, it will not react again no matter how much water you put on it. You can add paint on top of the surface as shown below.
I'm going to switch colors on you now - I made this tag but was not happy with so much red and pink. I wanted to add some blue so when the tag was completely dry I added some Broken China.