The search engines are where SEO comes from (Search Engine Optimization). You can use videos like I uses the previous video and images in each post or page you are adding on your website, they can be on platforms like Youtube or Vimeo or even on your own website but I would not advise being on your own website because it can block the entire internet bandwidth for the website when many people are watching it in the same time. Using big and many images can make a similar bandwidth block and the entire website, including the pages and post that don't have images, will load harder (in many seconds or minutes).
When you are writing your content remember that keywords and use them often in your text. If you can add headers in the test use the keywords in the headers and in your title. You should use only one h1 for your title, h2 for the main ideas or the section, h3 for the subsections and so on. Use bold text only when there are no headers left for it and you want to show some words (whatever they are) for the readers.
Keep writing about things you know best or you love, keep posting cool stuff and keep writing as often as you can.
