How to pick a workout shoe:
Have your feet sized in store.
Buy shoes at the end of the day, when your feet are the most swollen.
Wear the same kind of sock you'll wear with the shoe.
Try the shoes on.
Be sure shoes have a wide toe box.
Check that there's 1/2" between toes and front of shoe.
Make sure shoes aren't too narrow.
Heel should not slip.
Shoes should be comfortable – no "breaking in."