What preset should I use?

You don't need to use any preset. Presets are just a collection of plugins which makes it easier to use if you want to transpile a set of features (for instance all ES2015 with preset-es2015). But when you want to transpile only a selection of these features, you only include the corresponding plugins.

What plugins should I include so I can use async/await?

Because Node 6 supports generators, you can use transform-async-to-generator with the following .babelrc:

{

  plugins: [transform-async-to-generator]

}

And of course you would need to add plugins if you need to transpile more unsupported features.

Alternative babel-preset-env

babel-preset-env automatically determines what plugins you need for the specified environment. This will not include any plugins that are not necessary. To specify your current Node version you would use this .babelrc:

{

  presets: [

    [env, {

      targets: {

        node: current

      }

    }]

  ]

}