My favorite ULS logging PowerShell command is described here: http://technet.microsoft.com/en-us/library/ff607721.aspx. The Merge-SPLOgFile cmdlet pulls trace log entries from all farm computers into a single log file on the local computer and it works in Project Server 2010 and 2013, too.
I can hand this link to customers and they can run the Merge-SPLogFile command from PowerShell. The result is a single output file they can easily upload for me to review. The real benefit to this command, as someone who does troubleshooting remotely, is that I get all ULS entries from all the servers combined. Pretty neat.
Merge-SPLogFile -Path "c:\mergelog\log.txt" -Overwrite -level High -StartTime "03/25/2014 12:00" -EndTime "03/25/2014 12:59"