What is the proper way to access Redux store?

The best way to access your store through a component is using the connect() function. Actually creates a new component that wraps around your existing one! This pattern is called Higher-Order Components, and is generally the preferred way of extending a component’s functionality in React. This allows you to map state and action creators to your component, and have them passed in automatically as your store updates. Let’s take an example of FilterLink component using connect,

import { connect } from 'react-redux'
import { setVisibilityFilter } from '../actions'
import Link from '../components/Link'

const mapStateToProps = (state, ownProps) => {
  return {
    active: ownProps.filter === state.visibilityFilter
  }
}

const mapDispatchToProps = (dispatch, ownProps) => {
  return {
    onClick: () => {
      dispatch(setVisibilityFilter(ownProps.filter))
    }
  }
}

const FilterLink = connect(
  mapStateToProps,
  mapDispatchToProps
)(Link)

export default FilterLink

Due to it having quite a few performance optimizations and generally being less likely to cause bugs, the Redux devs almost always recommend using connect over accessing the store directly (using context API).

class MyComponent {
  someMethod() {
    doSomethingWith(this.context.store);
  }
}