To use dofollow and nofollow links strategically, you need to consider your goals, your audience, and your relationship with the linked website. Generally, you should use dofollow links for links that are relevant, trustworthy, and beneficial to your users, such as links to authoritative sources, references, or partners. You should use nofollow links for links that are irrelevant, untrustworthy, or potentially harmful to your users, such as links to paid ads, sponsored posts, or user comments.
However, there are some exceptions and nuances to this rule. For example, you may want to use nofollow links for links to your competitors, to avoid giving them an SEO advantage. You may also want to use nofollow links for links to your own pages that are not important for SEO, such as login pages, privacy policies, or terms and conditions. On the other hand, you may want to use dofollow links for links to your social media profiles, to boost your social signals and engagement.