Nowadays, it is very easy to use BBCode but it is so much more clean and beautiful and easy to use when you use an extension. Subscribe to brand new hacks & showcases: http://bit.ly/OSBsub
Simpler guide for BBCode only: https://www.youtube.com/watch?v=mxce5nKIe5k

Extension download: https://www.phpbb.com/customise/db/extension/mediaembed/