What I've settled on is (after deauthorizing any respective accounts):
Enable FileVault if not already enabled, and allow it to encrypt all contents on the computer's drive(s) (I believe this step is more important than ever before)
Then, boot into the Recovery HD (or, create an install/recovery USB flash drive, boot into USB Recovery drive), open Disk Utility, (unlock the drive(s) if necessary), erase the partition(s) with any OS(s)/User Files
Then, close the Disk Utility, and select the option to reinstall OS X