A forum can add value to your website especially if you have an active community behind it that not only engages with your great content but also gives them the power to interact with each other. You can add forums to your Webflow site with Discourse. Fun fact : Webflow's forum runs on Discourse.
Sort and Filter content on Webflow with MixitUp3. MixItUp 3 is a dependency-free library for animated filtering and sorting. Great for managing any categorized or ordered content like portfolios, galleries, and blogs. It can be used both with static and dynamic content. I have provided the link below of a very detailed page explaining how to make this work. Tutorial created by Anna Sabatini.
Marquee is an animation effect for web pages, this trick is good for scroll text, testimonials, company logos, etc. It can be achieved with Webflow's animation. The link below is a video of Pixel Geek explaining how it's done.
10 tips for creating a responsive website in Webflow, tutorial by Jose Ocando
Build a website where you can display a preview of your Webflow template and sell them for a good price. There are two ways you can do this, sell each template individually and once you receive the payment you can transfer the site to their site. The other way works well when you have a lot of templates, you can create a membership site and have all the templates available for paying members. Membership functionality can be added easily with Memberstack. (the link below is an affiliate link of Memberstack)