Unfortunately the suggested video functionality is all setup on YouTube's side of the fence, however you can get around by taking the following step, depending on the URL that you use:
If the URL contains a '?' character, then you will need to add this to the end of the URL '&rel=0'
So for example the URL from the address bar in a browser:
If you're using the 'share' button in YouTube the URL won't contain a '?' so you will need to add this to the end of the URL '?rel=0'
So this URL:
Still having trouble, or have a question you can't find the answer to? Let us know.