Define one primary goal per screen.

This will streamline your design efforts and your users' experiences immensely. It also allows you to be crystal clear on what that page's function is and how you can measure its effectiveness.

Simplify your product's navigation.

Experts in cognition say that a parent menu or nav should never have more than 5±2 options. This coincides with the number of items the average human can maintain in their short term memory. Staying at this limit allows for users to more easily create a cognitive map of your site.

Always allow for users to leave the way they came in. Just as in entering a house and not being able to find the door again, you never want to disorient your visitors. Breadcrumb Links solve this problem well.

Be consistent

Define your style early and maintain that similarity on every page, whether it's in style and structure. A full-blown design system might not be in the cards for your project, but I love taking a moment to collect text styles, color pallet, and a handful of buttons that I think I'll need.

Design for the human eye's scanning pattern.

The average internet user often scans web pages in the shape of an "F" or a "Z" pattern.(Source)
Hierarchy is the thing we're looking for here, especially if your product has words on a page (it probably does.) — something large at the top to cognitively anchor a user, and then scannable details that follow down the spine of the page.