As a product manager working on web related products, there are lots and lots of resources that can teach you something on building a better user experience.

Knowing a couple of basics can get you a long way while evaluating designs and testing new features. Obviously, there are some things that cannot be applied right away and need a proper AB test to be confirmed in your case.

My personal shortlist:

1. A clear next action: in every screen where you want your user to do something, there should be a really clear next action. If there are multiple links or buttons, someone should be able to point out the most important one just by the looks of it. Even better: remove options that aren’t directly needed.
2. Give sense of control: in most situations, users should feel in control. You want to delight your users and surprise them, but at the same time, users should know what will happen before they press a button or click a link. A simple way to do this is by making sure the link tells what will actually happen (“Enter personal details” instead of saying “Next” or “Continue”). Good design is honest. Make things as clear as you can.
3. Eliminate user input: especially with forms, you’ll be able to help your users. Adding some intelligence and magic to your forms will make it a lot easier: provide instant feedback, autofocus the keyboard on showing a form and accepting all kinds of input to name a few.
4. Stick with familiar: platform guidelines exist for a reason. Users like stuff they recognize. If you want to try new and groundbreaking stuff, make sure to test this on a small group. You might very well be wasting your time. Often, sticking to the old and familiar way of doing things will give the best results.