To create an early bundle, go to your nominated environment. Select the related features to bundle and click 'Create bundle':

Enter a name for your bundle and click 'Merge into bundle':

If the bundle was successfully created, you'll see a green success banner and the option to view your bundle:

Once your bundle is created, it appears in the open list with a 'Bundle' label so you can tell it apart from an individual feature:

You can also see the list of individual features in the bundle under the 'Bundle features' section in the PR side panel. From here you can:

If features being added to a bundle conflict with each other, or with the bundle branch itself, we'll attempt to merge as many as possible automatically.

The remaining features will be marked as having a conflict, which must be resolved before they can be merged into the bundle. This process is described here.