Simple example w/ propTypes...

propTypes-example.js

import React, {PropTypes} from 'react'

const examplePropTypes = {
  // Require the title
  title: PropTypes.string.isRequired,
  // Optional function
  doThisWhenClicked: PropTypes.func,
  // Some array of "special things with a certain shape"
  specialThings: PropTypes.arrayOf(
    PropTypes.shape({
      id: PropTypes.number.isRequired,
      name: PropTypes.string.isRequired,
      deleteMe: PropTypes.func.isRequired,
      specialOptionalAttribute: PropTypes.any,
      tags: PropTypes.arrayOf(PropTypes.string),
    })
  ).isRequired,
}

const MyComponent = (props) => {/*...*/}
MyComponent.propTypes = examplePropTypes

const MyComponent = React.createClass({
  propTypes: examplePropTypes,
  // ...
})

class MyComponent extends React.Component {/*...*/}
MyComponent.propTypes = examplePropTypes