Setup TypeScript with React

Prerequisites

good understanding of React
familiarity with TypeScript Types (2ality's guide is helpful. If you’re an absolute beginner in TypeScript, check out chibicode’s tutorial.)
having read the TypeScript section in the official React docs.
having read the React section of the new TypeScript playground (optional: also step through the 40+ examples under the playground's Examples section)

This guide will always assume you are starting with the latest TypeScript and React versions. Notes for older versions will be in expandable <details> tags.

VS Code Extensions

refactoring help https://marketplace.visualstudio.com/items?itemName=paulshen.paul-typescript-toolkit
R+TS Code Snippets (there are a few...)
- https://marketplace.visualstudio.com/items?itemName=infeng.vscode-react-typescript
- https://www.digitalocean.com/community/tutorials/the-best-react-extension-for-vs-code
TypeScript official extension https://code.visualstudio.com/docs/languages/typescript

React + TypeScript Starter Kits

Cloud setups:

TypeScript Playground with React just if you are debugging types (and reporting issues), not for running code
CodeSandbox - cloud IDE, boots up super fast
Stackblitz - cloud IDE, boots up super fast

Local dev setups:

Next.js: npx create-next-app -e with-typescript will create in your current folder
Create React App: npx create-react-app name-of-app --template typescript will create in new folder
Vite: npm create vite@latest my-react-ts-app -- --template react-ts
Meteor: meteor create --typescript name-of-my-new-typescript-app
Ignite for React Native: ignite new myapp
TSDX: npx tsdx create mylib for Creating React+TS libraries. (in future: TurboRepo)

Other tools

Less mature tools still worth checking out:

Snowpack: npx create-snowpack-app my-app --template app-template-react-typescript
Docusaurus v2 with TypeScript Support
Parcel
JP Morgan's modular: CRA + TS + Yarn Workspaces toolkit. yarn create modular-react-app <project-name>

Manual setup:

Basarat's guide for manual setup of React + TypeScript + Webpack + Babel
In particular, make sure that you have @types/react and @types/react-dom installed (Read more about the DefinitelyTyped project if you are unfamiliar)
There are also many React + TypeScript boilerplates, please see our Other Resources list.

Import React

import * as React from "react";
import * as ReactDOM from "react-dom";

This is the most futureproof way to import React. If you set --allowSyntheticDefaultImports (or add "allowSyntheticDefaultImports": true) in your tsconfig.json you can use more familiar imports:

import React from "react";
import ReactDOM from "react-dom";

Explanation

Why allowSyntheticDefaultImports over esModuleInterop? Daniel Rosenwasser has said that it's better for webpack/parcel. For more discussion check out https://github.com/wmonk/create-react-app-typescript/issues/214

You should also check the new TypeScript docs for official descriptions between each compiler flag!