As important as the content of your website, it is to make your website visible on the web. To increase your ranking in Google and similar searchengines, onsite search engine optimization is important.
The current status of your search engine optimization can be checked on https://developers.google.com/speed/pagespeed/insights/?hl=de.
Most wordpress-themes are very bad at this out of the box but can be improved with the help of some easy to configure plugins.
The following categories are tested:
Avoid landing page redirects
Is usually not an issue with wordpress, except u did something out of the ordinary.
There is two ways to enable compression. You can add the necessary changes manually to your .htaccess (or web.config in case of windows-server) or you can use the plugin W3-Total-Cache to do this for you.
CSS minification is done by several plugins. I’m usually using W3 Total Cache for this, as I’m using that plugin for a lot of other stuff too.
An easy workarround would be to manually minify all your css files. There are many online-tools which will help you to do this. Keep the original ones though, as working on minified files is a huge pain in the ass.
This is a little harder. Again W3 Total Cache will do this for you, but it does not work smoothly with every theme.
If you write your theme yourself you can of course write it without linebreaks and so on.
Another thing W3 Total Cache will do for you.
Prioritize visible content
This is one of the harder thing to do. You will no get arround coding. Basicly you should write your theme in a way that visible content will be loaded before content that is not in the inital viewport.
Reduce server response time
A slow response time can have many reasons. WordPress is not the fastest cms. Make sure your hosting is sufficent and install a caching plugin like WP Super Cache or W3 Total Cache.
This is even more tricking the point 6. If your theme is not optimized for this I would bench it.
Optimizing images means making them as small as possible without loosing any quality. There is a range of plugins out there wich will do this automatically for every image you upload. Some free, some with a monthly fee. Most of the plugins will upload your pictures to another server for compression. I like EWWW Image Optimizer as it will do the compression on your own system. You need some tools installed though which are not availible on all webhosts. No harm in trying it out though.
Leverage browser caching
This point is about communication your users which parts of the website they should save instead of downloading them every time (like i.e. images). You can fo this manually by altering the .htaccess (web.config) or with a plugin like i.e. W3 Total Cache.
What plugins are you using? I would love to have a discussion in the comments!