I'm not sure how much good feedback you can get from someone who never watches you work. You can absolutely get advice from people that helps you, but is it really that much better than reading books and blogs?
This is great advice. A lot of people are busy but there are some who are more than happy to be mentors, it's just a matter of finding them. Could become a numbers game which is worth it imo.
Then simply reach out on linked-in, introduce yourself, expand on something which you have in common to establish some familiarity and clearly state that you would be interested in some advice/mentoring to achieve your goals. You will likely get a reply that your mentor is too busy for this, but maybe he/she can spare an hour every other month, which would already be plenty and super useful.