Repetition in art can be a very powerful technique to draw the viewer into your work. Andy Warhol is one of the first artists that comes to mind when it comes to repetition. Have a look at his Marilyns or Campbell’s Soup cans.
You can search for repeating patterns in the outside world and you may come across many such opportunities as shadows (as shown in the photo above) or other objects. It’s especially good for minimalistic and abstract compositions.
You can also create repetition on computer using Photoshop or a number of other computer or phone apps, as shown here both above and below.
In spoken or written words, repetition can be a tool to place more meaning on what’s being said. To place an emphasis on it. The same can also be true in the visual realm.
Repetition can also create a sense of movement and rhythm. A composition that utilizes repetition will frequently use color or shapes as a dominate element.
And repetition in repeating the same process over and over again can create boredom. That is why I am forever looking at new methods to create works. Try repetition, you might like it.