A Pattern for Reusable Repository Design in Laravel - http://www.slashnode.com/reusable-repository-design-in-laravel/

UserRepository.php

<?php namespace Acme\Repositories;

use Acme\Abstracts\Repository as AbstractRepository;

class UserRepository extends AbstractRepository implements UserRepositoryInterface
{
	// This is where the "magic" comes from:
	protected $modelClassName = 'User';
	
	// This class only implements methods specific to the UserRepository
	public function findByUserName($username)
	{
		$where = call_user_func_array("{$this->modelClassName}::where", array($username));
		return $where->get();
	}
}