When spinning up new machines and joining them to the domain at least 2 reboots are required. One when you rename the machine (Windows used to let you specify the name at install time – the removal of that feature was a step backwards) and the other when you join it to the domain.
I was looking at the help file for Add-Computer and discovered you can rename the machine as you join it to the domain. Miss one reboot and get the build finished quicker.
$cred = Get-Credential manticore\richard
Add-Computer -Credential $cred -DomainName manticore -NewName W12R2Web02 -Restart –Force
Nice and simple – I like this.