Step 1: graduate.
Step 2: force your schedule to become consistent (i.e. get a 9-5pm job). At this point, it is important not to become a workaholic. Don’t devote your life to your job.
Step 3: realize you have actual free time now.
Step 4: dedicate that free time to some hobbies or activities.
*Note: may take a bit more personal discipline and effort than what I outlined above.