I prefer to own all the directories and files (it makes working with everything much easier), so, go to your laravel root directory:
cd /var/www/html/laravel
>> assuming this is your current root directory
sudo chown -R $USER:www-data .
sudo find . -type f -exec chmod 664 {} \;
sudo find . -type d -exec chmod 775 {} \;
Whichever way you set it up, then you need to give read and write permissions to the webserver for storage, cache and any other directories the webserver needs to upload or write too (depending on your situation), so run the commands from bashy above :
sudo chgrp -R www-data storage bootstrap/cache
sudo chmod -R ug+rwx storage bootstrap/cache
(Answer found on https://stackoverflow.com/questions/30639174/how-to-set-up-file-permissions-for-laravel#answer-37266353)