<?php

namespace App\Traits;

trait Foo
{
    /**
     * Method description.
     *
     * @return string
     */
    public function methodName()
    {
        return "Hello World";
    }
}

<?php

namespace App\Http\Controllers;

use App\Traits\Foo;
use App\Http\Controllers\Controller;

class PostController extends Controller
{
    use Foo;

    // your controller methods HERE.
}