What does it mean in practice?
Let's take my website hisevilness.com and this article as an example, it is a personal webpage of a person who writes about technology as a hobby and the YMYL would be my work in the Defense industry. And the website content is a whole spectrum of subject matter and not a single subject. I do not buy links nor do a advertise on the web all my work is organic and spreads by word to mouth.
My reason to write this article is simply that I also do overclocking of pc hardware which can also be found on the website and SEO is like overclocking your website and I like to share this on my website. In order to establish this, an algorithm or reviewer will look at my social media platforms, steam profile and other content regarding the subject matter on this website. So if you want to establish a reputation link to your social media profiles, profiles like steam etc. This will reflect who you are a person, in the case of a business you will have separate profiles so you should link and backlink from those to your website. Try to find older examples of any of your activities or business activities mention and link to those. Share your links on social media like tweet out if you finish an article so people can find it that way. Put your work on Pinterest but ensure you do not have a small sample size of backlinks but a wide variety of relevant backlinks to your site. By relevant is that I get backlinks from overclocking sites to my articles and not from a car sale shop. A secondary source is my online gaming adventures there a logo's, screenshots of scores etc showing that I also spend a considerable amount of time working with hardware and using that hardware. The YMYL would be my work while most of this would not even be on the internet and is even classified it does have mentions in video's like a Peshmarga T-55 tank bouncing of an ATGM(Anti-Tank-Guided-Missile)of the front armor by angling its armor just before impact resulting in a non-lethal impact and the survival of the T-55 tank crew. Google algorithms and reviewers can find these all on YouTube another Google platform. So ensure if you have YMYL content Google can find this by having an online profile that reflects that. While most people will have a much easier time getting their YMYL by getting reviews I, unfortunately, can not due to the nature of my work.
The end user experience is important and is made easier by providing content that has a good markup in terms of the coding and in terms of the markup of the actual text. The way your code is presented to Google is important do not clutter your website with crap. Here is a snapshot of my website by GTmetrix.com: https://gtmetrix.com/reports/www.hisevilness.com/NwgNb4Cs My PageSpeed score(Google) is 96% and 83% for Yslow(Yahoo). Run the GTmetrix tool on your own website and see where you can make improvements these will cover both the coding and the content. Just to highlight on major scoring aspect is the image size in size as well as dimension make sure you serve images that fit your page and that they are not resource intensive in terms of size(kb/mb). An easy way to optimize your images is by using https://tinypng.com/ and re-upload images that were too big in size to a smaller size also speeding up the user experience in the process. Text markup it is important to remember not to spam caps or use H1 headers, use H1 header once to lead in the article then use H2 headers to lead in paragraphs and subparagraphs with H3 headers.
Content Delivery Network.