When you do something routinely, you do it often and regularly. Many people routinely brush their teeth before they go to bed and again when they wake up in the morning.
Something that's become a habit or an often repeated series of actions is done routinely. Your actual daily routine is one example of this — you might routinely eat cereal for breakfast, or routinely feed your cat at 5:00, for example. You can also say that a movie critic who always seems to find some fault with a film routinely trashes all your favorite movies. The French root is routine, "usual course of action," from route, "way or path."