If you simply have too many URLs on your site, Google might crawl a lot but it will never be enough. This can happen because of faceted search navigation for instance, or another system on your site that simply generates too many URLs. To figure out whether this is the case for you, it’s always wise to regularly crawl your own site. You can either do that manually with Screaming Frog’s SEO spider, or with a tool like Ryte.

Most often, you’ll want to use the noindex tag. You usually only want to use nofollow for affiliate links, links someone has paid you to create, or you receive a commission from. This is because you don’t want to “sell links”. When you add nofollow, it tells Google not to pass on your domain authority to those sources. Essentially, it keeps the web free of corruption when it comes to linking.