F - RenderMethodComponent.tsx

// Example

export class RenderMethodComponent extends React.Component {
  renderList = () => (
    <View>{this.props.items.map(() => (
      <Deeply><Nested><Views>
      </Views></Nested></Deeply>
    )}</View>
  );

  renderAddButton = () => (
    <View><Button onPress={this.onButtonPress}>Add</Button></View>
  )

  render() {
    return (
      <View>
        {this.props.items.length && this.renderList()}
        {this.props.addButton && this.renderAddButton()}
      </View>
    );
  }
}

Good - RenderComponents.tsx

// Better Example

const ListItem: React.SFC = () => (
  <Deeply><Nested><Views>
  </Views></Nested></Deeply>
);

const List: React.SFC<{ items }> => items.map(() => <ListItem />);

const AddButton: React.SFC<{ onButtonPress }> = (
  <View><Button onPress={onButtonPress}>Add</Button></View>
);

export class RenderComponentsComponent extends React.Component {
  render() {
    return (
      <View>
        {this.props.items.length && <List items={this.props.items} />}
        {this.props.addButton && <AddButton onButtonPress={this.onButtonPress} />}
      </View>
    );
  }
}