Laravel automatically handles HTTP exceptions and throws errors / redirects as it sees fit. Sometimes, this isn't an ideal behaviour. I was building an API and wanted to display custom messages for missing routes, forbidden and other errors. This can be done like this

1. Open app\Exceptions\Handler.php

2. If you want to handle missing models, paste following snippet in render method

if ($exception instanceof ModelNotFoundException) {
    return response()->json([
        'error' => 'Model not found'
    ], 404);
}

1. If you'd like to handle other HTTP exceptions, paste the following snippet instead

if ($this->isHttpException($exception)) {
    switch ($exception->getStatusCode()) {
        // not authorized
        case '403':
            return \Response::json([
                'error' => 'You are not allowed to access this'
            ], 403);
            break;

        default:
           return $this->renderHttpException($exception);
           break;
    }
}