Vertical navigation is a good fit for broad or growing IAs, but takes up more space than horizontal navigation. Ensure that it is left-aligned, keyword front-loaded, and visible.
Pain points are problems that occur at the different levels of the customer experience: interaction level, customer-journey level, or relationship level.
Card sorting is great for designing or evaluating an information architecture (IA), but can be hard to interpret. Dendrograms visualize the data which can help you make the necessary decisions which are rarely clear-cut but require tradeoffs.
If users don't use your search a lot, it's often because the search user interface is poorly designed. Here are the top guidelines for how to show the search feature on both desktop and mobile.