How and when to make puddles of watercolor

Supplies are at CozyLark.com I get tons and tons of questions about making puddles--how do you make them, and when do you use them? There are lots of reasons you might want a puddle of paint over pulling straight from the pan, like if you want to mix colors, if you want to make a lot of one color, and if you want to control the value of the color (that's how light or dark it is.) Once you know how to use puddles, you're well on your way to understanding watercolor!