Rather than just uploading a video to a general channel you can create a channel for
each keyword. As this targets just one keyword you can link back to that channel.
This does not work if it uploaded to your usual channel.
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Use Speech pad at https://www.speechpad.com/ to transcribe the video and put this
transcription in the description box by copying and pasting.

Few people do this but it can be picked up by the search engines.

If you don't want to pay someone to do this then you can write a script before you start and then use this to make the video. This will give you the transcription. be sure to use your keywords in the video and in the transcription.

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Tag the video. Get suggestions from Google suggest. Basically Google’s auto suggest
function aims to improve the usability of its search engine. Suggestions help the
searcher save time entering long phrases like “Samsung Galaxy S4”. Thanks to
Google Suggest, that term can be chosen after “Sams” is entered.