H1, H2, H3 etc. These are truly important. Using Headers & sub headers to organise and layout your page not only makes it easier to find relevant information and look more organised or attractive, it also optimises the page well.
However, consider the hierarchy of header tags. You should only use one H1 and then work your way down to H2 & H3 if necessary, jumping from a H1 to H3 is not as useful.
Don’t forget to add images & videos within your layout, this is important too. An eye catching and colourful page is more likely to increase interest and in turn increase the time spent on you page.