Bootstrap 3 classes are used by default for styling the forms. That can be modified by changing the configuration.

First, publish the package assets/configuration.

php artisan vendor:publish

This will create config file config/laravel-form-builder.php and folder with views in resources/views/vendor/laravel-form-builder.

Structure of the config needs to be like this: config.php file.

change values in defaults key as you wish.

If you would like to avoid typing in full namespace of the form class when creating, you can add default namespace to the config that was just published, and it will prepend it every time you want to create form:

<?php

// config/app/laravel-form-builder.php

return [
    'default_namespace' => 'App\Forms'
]

// app/Http/Controllers/HomeController

public function indexAction()
{
    \FormBuilder::create('SongForm');
}