Check out this post on silverlakestudio.com written by the always worth paying attention to Travis Whitmore. If you are an audio engineer using protools, then you know about shortcuts. Hitting Ctrl+S Saves your work, and it’s good to do this often so you don’t end up wasting hours of time. Instead of undoing bad takes, you can hit Ctrl+Period and it will abort the take, as if it never existed. Since it deletes the take permanently, there is no unnecessary audio piling up on your hard drive.
A good read for any Pro Toolers setting out:
Pro Tools Tip: Don’t Undo, Abort!