WP Optimize

At this moment I am using it (free version) for speeding up my website and it works really well. It took some (not too long) to dive into things and after that I managed to iron out some of the basic things I ran in to. Like minify, gzip, etc. You also need to make some exceptions when using WooCommerce, as the store pages need that. (I use an Ajax driven website) I noticed a good speed increase after activating this plugin and the fact that it squashes (smushes ;)) .jpeg files into .webp (compressed while keeping them rather lossless). My website relies heavily on images, so that helps a lot. Recommended!