WordPress’ comment system is incomplete. This plugin adds a lot of nifty little tricks to make comments on WordPress a lot more manageable.
XML sitemaps for PDFs
If your site has a lot of PDFs, this add-on to Yoast SEO is what you need to get them indexed.
Make sure tags are only live on your site when they actually add value, so when there’s more than a few posts in it. This makes sure your site has less (useless) tags.