Get to know your Alt (or Option) key with this Premiumbeat tutorial. Jason Boone lists six important functions of the alt key in Premiere Pro. Such functions include Ripple Delete, Replace, and Rearrange clips. I use these six functions all the time in Premiere Pro. Try experimenting with the alt key in other commands to see what "alternative" or "optional" functions you come up with.
Learn how to harness the power of the Alt key to drastically speed up your Premiere Pro video editing workflow. —Jason Boone, Premiumbeat Blog