Callouses and rough spots are the enemy of refined, pretty feet. That dead skin, now softened, will respond quickly and easily to clean-up.
For this step, you'll need an exfoliating scrub. Something made specifically for feet is nice, but anything containing large, rough crystals will get the job done (smooth microbeads won't do). You can make your own scrub at home by combining an oil or moisturizer with enough coarse-ground salt or sugar to produce a paste.
Massage it into each foot, focusing on the heels and outer surfaces. You may want to wear exfoliating gloves, which will make the job easier as well as protect your hands. Work on this for a couple of minutes, and rinse well. Go at any still-rough areas with a course foot file.
Gently scrape away any hardened cuticle edges with a dull mani/pedi stick (cuticle oil is a nice pre-treatment, but not strictly necessary), and push them back. Don't cut them. They protect your nails from bacteria.
Finally, dry thoroughly, because the next step does not mix well with moisture.