This is a guide to creating a timings report, nothing more, nothing less. For information on understanding your timings result, please see here.
Creating the data ( only applies to builds 1261 - 1537 )
This is not recommended for the latest Spigot builds.
First, stop your server to prevent overwriting of changes that will be made.
Access your bukkit.yml in your markup/text editor of choice.
Find the plugin-profiling boolean and change it from the default false to true.
Save changes and reupload if the file was received via FTP.
Recommended: Keep plugin profiling off!
It is recommended to keep plugin profiling setting off if you are on the latest Spigot builds where /timings on works.
It is encouraged to leave it off, and issue /timings on when you are experiencing lag, and collect about 1 minute of data.
Dumping the data and generating the report
Leave your server to run for at least 1 minute during the lag or until the spike you wish to analyze occurs.
Enter the command "/timings paste" either into your client ( if your account has the relevant permissions) or into your console.
Get the aikar.co link and using your knowledge or by posting it to the Performance Tweaking forum here, analyze it.
If you are not satisfied with the output or wish to cut it short just before a known lag spike, run "/timings reset" to reset your data and repeat this process.