Apart from SSD hosting upgrade, these are the method to take care to optimize your WordPress website.
Choose a good WordPress theme, test all the plugins you need before using, optimize images per page or post, install a caching plugin to cache, enable gzip compression, optimize WordPress database manually in MySQL in phpmyadmin if you know how to do it. Delete any unwanted things. Keep a clean database by removing unnecessary posts revisions using plugins. Delete plugin history with related plugin. Disable plugins whose function you don't need always.