Keep in touch
Keeping in touch with a mentor is your responsibility since it is a relationship born out of your initiation. Don't expect mentors to be in charge of your regular communication since they may be busy. Find time to send a thank you message after every session, state your interest in having more sessions, or simply share your insights after the session.
You can also message them a week later and describe your impressions of a book, article, online course, or resource your mentor recommended. If needed, you can suggest scheduling a meeting to discuss the topic in more detail.
Also, don't forget to share your wins! For example, if you followed a mentor's recommendation on conducting a user interview, tell them how it went and what revelations you received. Share your misfortunes too. Learning includes sharing both successes and failures.