Chances are you know other writers who are seeking feedback, or you’ve seen open calls asking for beta readers among the social media outlets in your life. So, as your schedule allows, volunteer your time, read their stuff, and critique it as constructively and thoughtfully as you can. Not only is this good karma, payable in the form of them reading your drafts in return, but it helps you see your own work more realistically, both its strengths and its flaws, when you get back to it.
It’s probably most useful if you choose to beta-read projects that are the kind of thing you like to read anyway, but it can also be a good stretch for your mind to try something different from your usual tastes. Most writers—as you know, being one—are grateful for any kind of feedback, whether from the typical reader of the genre in question or from someone less familiar with it, and you can really make a difference in your friend’s revision process by providing your thoughts. Be the change you want to see in the writing world, and help a colleague out!