This utility is SO useful! There are situations where a straight-forward tool for clicking at specific coordinates can make user interface scripting possible, including working around bugs in Mac UI Scripting. One example is that clicking any button in FileMaker Pro's developer interfaces that opens or closes a window forces your script to wait for 7 seconds before continuing, even though the interface itself is responsive. I use this utility to click any of those buttons/objects, which removes a lot of unnecessary delay in my scripts.
The documentation is very clear, and the command options are very easy to put together, as long as you have a basic understanding of shell commands. I put this in a sub-folder in my Application Support folder, then call it from AppleScript like this:
set clickCommandPath to ((path to application support from user domain) as string) & "NYHTC:cliclick"
set clickCommandPosix to POSIX path of clickCommandPath
do shell script quoted form of clickCommandPosix & space & "kd:cmd,shift kp:arrow-up ku:cmd,shift c:12,34"

That would emulate pressing command-shift-s, then clicking at the coordinates: 12, 34.