Here's a picture of my weather station (Davis 6153), which I put into service as of yesterday:
As you can see, I mounted it on a cedar mailbox post. The ISS is 5' AGL, over what is basically natural terrain for the desert here (no grass within probably 20 miles!). I raked the small stones away from the ground underneath to try to minimize the radiant heat from them - if the "berm" around it ends up interfering with drainage, I'll remove it.
The anemometer is mounted at 15' AGL. I know, not optimal height, but it's sited in a large, flat open area on the property and is a compromise for height/accuracy vs. ease of access if/when needed. The mast is 1 3/8" chain link top rail - a 10-foot section with another 5-foot section swaged and bolted atop it and capped by a PVC cap to avoid water inside it. I ran the anemometer cable through the mast and sealed the entry/exit points with silicone caulk. It looks clean and protects the cable from the elements, as well as avoiding the use of cable ties which fall victim to the blistering Arizona sun pretty quickly. You can see the entry point of the cable from the anemometer in the photo below:
The mast actually started with two 10' sections of top rail, but a quick test had me thinking that 20' would be too flexible unless I used guy wires. I cut it down to 15' and will try that - if it's too flimsy I'll consider my options. It's clamped to the mailbox post with 4 conduit clamps spaced evenly from the ground to the top of the post. It'll be interesting to see how it holds up in the occasional strong winds we get here during thunderstorms, as well as the seemingly ceaseless spring winds.
Any comments/suggestions are welcome. It's my first "real" weather station and I did a lot of research on siting before installing it, trying to obtain the best possible accuracy considering the native terrain and inherent compromises.