Air, the one in the middle, is light green with light white streaks worked into it, I've always found the color green above depicted air nicely (most likely due to a game called Lost Magic in which the shade was used for air). I then added small bumps into the clay, like bubbles, I pressed the bumps into the light white streaks to show them as if bubbles traveling along the wind. I put a hole big enough for spool on the top to hang with.
Water, the one on the right, is obviously blue, and has white streaks as well to show running water and its flow. The texture I gave to this one is basically roughing the spots up, I took a needle and poked a ton of tiny holes into it to do this. I put the holes along the white streaks like with the air symbol, to show moving rapids, or simply to highlight the lines. One other tiny detail is that I put silver clay with sparkling into it, the sparkles acting like shimmering water. This symbol is depicted upside down so I put no hole in it for spool.
Earth, the one on the left, this one I had a lot of fun with, I took the colors I wanted, many shades of green and brown coiled them, then rolled the coils together. As I did this I rolled it out yet again and twisted them together, this created a knotted or twisted wood effect as well as swirling them together. I also put little knots of wood on the ends. This symbol is also meant to be hung upside down.
Fire, not shown, unfortunately I had no yellow clay in which i wished to use for fire, so I borrowed some of my brothers, and instead of cooking right... It melted... So they were pretty much destroyed. However, I will describe them, I put red mainly with orange, yellow, and pink highlights, and along the highlights I used an exacto-knife to score lines. This highlighted them more, and made it look like they were flames. these also had holes on top being depicted upright. (I used pinks because a book series I read had a character named fire whose hair was all those colors and pink, one reason I put sparkling silver clay in the water element)
Alright that about does it for the elemental symbols, I hope you enjoyed the amount of detail that was put into these. If you want any just ask!~