For Facebook you don't actually have to be a good writer. You just share a link to the video and in the description write something like "Iceland is so cool, check out my travel vlog where I visit this cool geyser". Then, just replace "Iceland" with @Iceland and pic the one for the country from the suggested list. And make sure the post is public. For a privacy conscious person be easier if you have/create a Facebook page for your Youtube so people don't actually see the post straight from you.
You can also tag a lot of other things there too, like
@YOUTUBE, individual locations, resorts etc. I recently had a photo I shared on my Facebook page shared by the hotel on the hotel page as well when I tagged the hotel in the post I made.