How to right a good cover letter?

At the moment I am applying for jobs and desperate to find something else, I am so miserable where I am.

However I am not getting any hits. I am wondering if it is how I am structuring my cover letter. I try to keep it to about a page and cover my interest in the role, my skills and what I would be able to bring to it instead.

Has anyone got any cover letter tips or tricks? I change it for every role to suit the position. How do you structure them?

TIA

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